/*
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*/
#ifdef aimbot
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#endif
#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <set>
#include <queue>
#include <ostream>
#include <istream>
#include <typeinfo>
#include <iomanip>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <limits>
#include <fstream>
#include <array>
#include <list>
#include <bitset>
#include <functional>
#include <random>
#include <cstring>
#define mt make_tuple
#define x first
#define y second
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define umap unordered_map
#define uset unordered_set
#define elif else if
#define len(v) ((int)v.size())
#define f(i, n) for (int i = 0; i < (n); i++)
#define rof(i, n) for (int i = ((n) - 1); i >= 0; i--)
#define apply(v, act) for (auto &x : v) { act; }
#define fuck(args...) {string s = #args;deque<string> deq;\
string buf = "";int bal = 0;for (char c : s) {\
if (c == '(' || c == '[' || c == '{') {bal++;\
} else if (c == ')' || c == ']' || c == '}') {\
bal--;} else {if (bal == 0) {if (c == ',') {\
deq.pb(buf);buf = "";} else {if (c != ' ') {\
buf += c;}}}}}if (!buf.empty()) {deq.pb(buf);}\
smart_io::precall_print();smart_io::_print(deq, args);}
#define print \
smart_io::precall_print(); \
cout,
#define scan cin,
using namespace std;
char string_in_buffer[(int)260];
void fast_scan(int &x) { scanf("%d", &x); }
void fast_scan(long long &x) { scanf("%lld", &x); }
void fast_scan(unsigned long long &x) { scanf("%llu", &x); }
void fast_scan(double &x) { scanf("%lf", &x); }
void fast_scan(long double &x) { scanf("%Lf", &x); }
void fast_scan(char &x) {
scanf("%c", &x);
if (x == '\n') {
fast_scan(x);
}
}
void fast_scan(string &x) {
scanf("%s", string_in_buffer);
x = string(string_in_buffer);
}
template<class TFirst, class TSecond>
void fast_scan(pair<TFirst, TSecond> &p) {
fast_scan(p.first);
fast_scan(p.second);
}
template <class T>
void fast_scan(vector<T> &v) {
for (auto &x : v) fast_scan(x);
}
void fast_print(const int &x) { printf("%d", x); }
void fast_print(const long long &x) { printf("%lld", x); }
void fast_print(const unsigned long long &x) { printf("%llu", x); }
void fast_print(const double &x) { printf("%.15lf", x); }
void fast_print(const long double &x) { printf("%.15Lf", x); }
void fast_print(const char &x) { printf("%c", x); };
void fast_print(const string &x) { printf("%s", x.c_str());}
void fast_print(const char v[]) { fast_print((string)v); }
template<class TFirst, class TSecond>
void fast_print(const pair<TFirst, TSecond> &p) {
fast_print(p.first);
fast_print(' ');
fast_print(p.second);
}
template <class T>
void fast_print(const vector<T> &v) {
if (v.empty()) return;
fast_print(v[0]);
for (int i = 1; i < v.size(); i++) {
fast_print(' ');
fast_print(v[i]);
}
}
template <class T>
void fast_print(const vector<vector<T>> &v) {
if (v.empty()) return;
fast_print(v[0]);
for (int i = 1; i < v.size(); i++) {
fast_print('\n');
fast_print(v[i]);
}
}
template <class T>
void fast_print(const T &v) {
for (const auto &x : v) {
fast_print(x);
fast_print(' ');
}
}
using namespace std;
namespace smart_io {
string print_start = "";
string sep = " ";
bool first_print = false;
void precall_print() {
fast_print(print_start);
print_start = "\n";
first_print = true;
}
void _print(deque<string>) {}
template<class T, class... Args>
void _print(deque<string> names, T kek, Args... args) {
if (!first_print) {
fast_print("\n");
} else {
first_print = false;
}
fast_print(names.front());
fast_print(" = ");
fast_print(kek);
names.pop_front();
_print(names, args...);
}
} //namespace smart_io
template <class T>
ostream &operator,(ostream &os, const T &object) {
if (!smart_io::first_print) {
fast_print(smart_io::sep);
} else {
smart_io::first_print = false;
}
fast_print(object);
return os;
}
template <class T>
istream &operator,(istream &is, T &object) {
fast_scan(object);
return is;
}
namespace typedefs {
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef long double ld;
}
namespace numbers_operation {
template<class T>
T floor_mod(T a, T b) {
if (a % b == 0) return 0;
if (a >= 0 && b >= 0) return a % b;
if (a <= 0 && b <= 0) return a % b;
return abs(b) - (abs(a) % abs(b));
}
}
using namespace numbers_operation;
using namespace typedefs;
const ll MOD = 1e9 + 7;
int n;
vector<pii> v;
struct Node {
Node *l = NULL, *r = NULL;
int value = 0;
int tl, tr;
bool is_list() {
return tl + 1 == tr;
}
bool included_by(int ql, int qr) {
return ql <= tl && tr <= qr;
}
bool intersects(int ql, int qr) {
return !(qr <= tl || tr <= ql);
}
Node(int _tl, int _tr) {
tl = _tl;
tr = _tr;
if (!is_list()) {
int mid = (tl + tr) / 2;
l = new Node(tl, mid);
r = new Node(mid, tr);
}
}
void upd_zero(int ql, int qr) {
if (is_list()) {
value = 0;
} else {
if (l->intersects(ql, qr)) {
l->upd_zero(ql, qr);
}
if (r->intersects(ql, qr)) {
r->upd_zero(ql, qr);
}
value = 0;
}
}
int query(int ql, int qr) {
if (included_by(ql, qr)) {
return value;
} else {
int rez = 0;
if (l->intersects(ql, qr)) {
rez += l->query(ql, qr);
}
if (r->intersects(ql, qr)) {
rez += r->query(ql, qr);
}
return rez;
}
}
void inc(int i, int d) {
if (is_list()) {
value += d;
} else {
if (i < l->tr) {
l->inc(i, d);
} else {
r->inc(i, d);
}
value = l->value + r->value;
}
}
};
struct Event {
int x;
int id;
bool open = false;
Event() {}
Event(int _x, int _id, bool _open) {
x = _x;
id = _id;
open = _open;
}
};
vector<Event> es;
vector<vector<int>> g;
vector<int> color;
void dfs(int v) {
for (int sub : g[v]) {
if (color[sub] == color[v]) {
print 0;
exit(0);
}
if (color[sub] == 0) {
color[sub] = 3 - color[v];
dfs(sub);
}
}
}
struct SUS {
vector<int> up;
SUS(int n) {
up.resize(n);
f(i, n) {
up[i] = i;
}
}
int get_root(int v) {
if (up[v] == v) return v;
return up[v] = get_root(up[v]);
}
void merge(int a, int b) {
a = get_root(a);
b = get_root(b);
up[a] = b;
}
int comps() {
set<int> roots;
f(i, len(up)) {
roots.insert(get_root(i));
}
return len(roots);
}
};
signed main(signed argc, char *argv[]) {
{
scan n;
v.resize(n);
scan v;
g.resize(n);
}
{
f(i, n) {
pii p = v[i];
es.emplace_back(p.x, i, true);
es.emplace_back(p.y, i, false);
}
}
{
sort(es.begin(), es.end(), [](Event a, Event b) {
return a.x < b.x;
});
}
{
SUS sus(n);
vector<set<int>> opens;
vector<pii> edges;
for (Event e : es) {
if (e.open) {
opens.pb({e.id});
} else {
int i = len(opens) - 1;
int pref = -1;
set<int> all;
while (!opens[i].count(e.id)) {
int __mn = v[*opens[i].begin()].y;
// for (int x : opens[i]) {
// __mn = min(__mn, v[x].y);
// }
if (__mn < pref) {
print 0;
return 0;
}
// for (int x : opens[i]) {
// pref = max(pref, v[x].y);
// }
pref = v[*opens[i].begin()].y;
i--;
}
int base = *opens[i].begin();
int base_op = i + 1 < len(opens) ? *opens[i + 1].begin() : -1;
if (e.id == 2) {
// print len(opens[1]), *opens[1].begin(), base, i;
}
if (i + 1 < len(opens)) {
// print "!", "ADD", base, *opens[i + 1].begin();
// sus.merge(base, *opens[i + 1].begin());
edges.emplace_back(base, *opens[i + 1].begin());
}
for (int j = i + 2; j < len(opens); j++) {
for (int x : opens[j]) {
opens[i + 1].insert(x);
}
// print "ADD", base, *opens[j].begin(), v[e.id];
sus.merge(base_op, *opens[j].begin());
}
while (len(opens) > i + 2) {
opens.pop_back();
}
opens[i].erase(e.id);
if (opens[i].empty()) {
opens.erase(opens.begin() + i);
}
}
}
for (pii e : edges) {
g[sus.get_root(e.x)].pb(sus.get_root(e.y));
g[sus.get_root(e.y)].pb(sus.get_root(e.x));
}
ll rez = 1;
color.resize(n);
f(i, n) {
int v = sus.get_root(i);
if (color[v] == 0) {
rez *= 2;
rez %= MOD;
color[v] = 1;
dfs(v);
}
}
print rez;
}
}
