#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 1e6 + 10;
int p[maxn * 2 + 100], n;
struct range{
int l, r;
bool operator < (const range &p) const {
return l == p.l ? r < p.r : l < p.l;
}
} v[maxn];
bool cant(int i, int j) {
return (v[i].l < v[j].l && v[j].l < v[i].r && v[j].r > v[i].r);
}
int find(int u) { return p[u] == u ? u : p[u] = find(p[u]); }
void construct() {
sort(v, v+n);
range q[n];
for(int i = 0; i < n; i++)
q[i] = {v[i].l, i};
for(int i = 0; i <= 2*n; i++)
p[i] = i;
for(int i = 0; i < n; i++) {
range xx = {v[i].r, 0};
int x = lower_bound(v, v+n, v[i]) - v;
int y = upper_bound(v, v+n, xx) - v;
for(int j = x; j <= y; j++) {
if(cant(i, j) || cant(j, i)) {
if(find(i) == find(j + n) || find(i + n) == find(j)) {
cout <<"0\n"; exit(0);
}
p[find(i)] = find(j);
p[find(j+n)] = find(i);
p[find(i+n)] = find(j);
}
}
}
}
int main(int argc, char const *argv[]) {
#ifdef LOCAL_TESTING
freopen("in", "r", stdin);
#endif
cin >> n;
for(int i = 0; i < n; i++)
cin >> v[i].l >> v[i].r;
construct();
ll ret = 1;
for(int i = 0; i < n; i++)
if(p[i] == i) {
ret = ret * 2 % ll(1e9 + 7);
}
cout << ret << endl;
}
