///
#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
#define sz(x) (int)x.size()
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
// for random generations
// mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
mt19937 myrand(373);
// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
fastIO();
if(str == "input") {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
} else {
// freopen("skis.in", "r", stdin);
// freopen("skis.out", "w", stdout);
}
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const long long mod = 1e9 + 7;
const int N = 2e6 + 10;
vector<int> adj[N];
int st[N], en[N];
int vis[N];
int n;
void dfs(int node, int parent) {
for(auto i: adj[node]) {
if(vis[i]) {
if(vis[i] != 3 - vis[node]) {
cout << 0 << '\n';
exit(0);
}
continue;
}
vis[i] = 3 - vis[node];
dfs(i, node);
}
}
long long binPowByMod(long long a, long long b) {
a %= mod;
long long res = 1;
while (b > 0) {
if (b & 1)
res = res * a % mod;
a = a * a % mod;
b >>= 1;
}
return res;
}
void solve_() {
cin >> n;
vector<pair<int, int>> vec;
for(int i = 1; i <= n; i++) {
int a, b; cin >> a >> b;
st[a] = i;
en[b] = i;
//
vec.emplace_back(a, b);
}
int add = 0;
for(int it = 0; it < sz(vec); it++) {
for(int i = vec[it].first + 1; i < vec[it].second; i++) {
if(st[i]) {
int cur = st[i] - 1;
if(vec[cur].second > vec[it].second) {
adj[it].push_back(cur);
add++;
}
} else {
int cur = en[i] - 1;
if(vec[cur].first < vec[it].first) {
adj[it].push_back(cur);
add++;
}
}
}
}
int cnt = 0;
for(int i = 0; i < n; i++) {
if(!vis[i]) {
vis[i] = true;
dfs(i, -1);
cnt++;
}
}
assert(add <= 5 * n);
cout << binPowByMod(2, cnt) << '\n';
}
int main() {
setIO();
auto solve = [&](int test_case)-> void {
for(int i = 1; i <= test_case; i++) {
solve_();
}
};
int test_cases = 1;
// cin >> test_cases;
solve(test_cases);
return 0;
}
