/*
ID: varunra2
LANG: C++
TASK: ports
*/
#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif
#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e9
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second
const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;
#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions
int n;
VII vals;
VI par;
VI siz;
MPII mp;
void init() {
par.resize(2 * n);
siz.assign(2 * n, 1);
vals.resize(n);
iota(all(par), 0);
}
int find(int x) {
while (par[x] != par[par[x]]) par[x] = par[par[x]];
return par[x];
}
bool same(int x, int y) { return find(x) == find(y); }
bool merge(int x, int y) {
x = find(x);
y = find(y);
if (x == y) return false;
if (siz[x] < siz[y]) swap(x, y);
par[y] = x;
siz[x] += siz[y];
return true;
}
int main() {
// #ifndef ONLINE_JUDGE
// freopen("ports.in", "r", stdin);
// freopen("ports.out", "w", stdout);
// #endif
cin.sync_with_stdio(0);
cin.tie(0);
cin >> n;
init();
for (int i = 0; i < n; i++) {
cin >> vals[i].x >> vals[i].y;
}
sort(all(vals));
for (int i = 0; i < n; i++) {
auto start = mp.lower_bound(vals[i].x);
auto end = mp.lower_bound(vals[i].y);
while (start != end) {
merge(i, start->y + n);
merge(i + n, start->y);
// if (same(start->y, prev(end)->y)) break; // this line is important
// it keeps it from becoming O(n ^ 2)
start++;
}
mp[vals[i].y] = i;
}
for (int i = 0; i < n; i++) {
if (same(i, i + n)) {
cout << "0\n";
return 0;
}
}
ll ret = 1;
for (int i = 0; i < n; i++) {
if (find(i) == i) {
ret *= 2;
ret %= MOD;
}
}
cout << ret << '\n';
return 0;
}
