// oooo
/*
har chi delet mikhad bebar ~
gitar o ba khodet nabar! ~
;Amoo_Hasan;
*/
#include<bits/stdc++.h>
#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
#pragma GCC target("avx2,fma")
using namespace std;
typedef long long ll;
typedef long double ld;
#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
constexpr ll inf = 1e18, N = 1e6 + 10, mod = 1e9 + 7, pr = 1000696969;
bool flag, color[N], mark[N];
int a[N], b[N];
vector<int> G[N];
bool okay(int i, int j) {
if(a[i] > a[j]) swap(i, j);
return b[j] > b[i] && a[j] < b[i];
}
void dfs(int x) {
mark[x] = 1;
for(auto &i : G[x]) {
if(mark[i]) {
if(color[i] == color[x]) flag = 1;
continue;
}
color[i] = color[x] - 1;
dfs(i);
}
}
ll poww(ll x, int y) {
ll res = 1;
for(; y; y /= 2, x = x * x % mod) {
if(y & 1) {
res = res * x % mod;
}
}
return res;
}
int main() {
ios :: sync_with_stdio(0), cin.tie(0);
int n; cin >>n;
for(int i = 1; i <= n; i++) {
cin >>a[i] >>b[i];
}
for(int i = 1; i <= n; i++) {
for(int j = i + 1; j <= n; j++) {
if(okay(i, j)) {
G[i].push_back(j), G[j].push_back(i);
}
}
}
int colorcnt = 0;
for(int i = 1; i <= n; i++) if(!mark[i]) colorcnt++, dfs(i);
if(flag) cout<<0;
else cout<<poww(2, colorcnt);
return 0;
}
