#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
using namespace std;
const int N = 1e6 + 5;
const int mod = 1e9 + 7;
pair <int, int> a[N];
int id[2 * N];
int c[N];
int add[N];
int nxt[N];
int par[N];
int n;
int getnxt(int u) {
return (nxt[u] == u || nxt[u] == 0) ? u : (nxt[u] = getnxt(nxt[u]));
}
int getpar(int u) {
if (par[u] < 0)
return u;
int p = getpar(par[u]);
c[u] = c[par[u]] ^ 1;
return p;
}
bool join(int u, int v) {
if (getpar(u) == getpar(v)) {
if (c[u] == c[v]) {
cout << 0;
exit(0);
}
return false;
}
u = getpar(u);
v = getpar(v);
if (par[u] > par[v])
swap(u, v);
par[u] += par[v];
par[v] = u;
return true;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
for (int i = 1; i <= n; i++)
cin >> a[i].fi >> a[i].se;
sort(a + 1, a + n + 1);
for (int i = 1; i <= n; i++) {
id[a[i].fi] = i;
id[a[i].se] = -i;
}
for (int i = 1, cur = 0; i <= 2 * n; i++) {
int u = abs(id[i]);
if (id[i] > 0) {
nxt[u] = u;
par[u] = -1;
cur = u;
} else {
int lo = u;
int hi = n + 1;
while (hi - lo > 1) {
int mid = (lo + hi) >> 1;
int nxtmid = getnxt(mid);
if (nxtmid <= cur && getpar(nxtmid) == getpar(u))
lo = mid;
else
hi = mid;
}
if (lo > u)
join(u, lo);
for (int j = getnxt(hi); j <= cur; j = getnxt(j + 1))
join(u, j);
nxt[u] = u + 1;
}
}
int ans = 1;
for (int i = 1; i <= n; i++)
if (par[i] < 0)
ans = ans * 2 % mod;
cout << ans;
return 0;
}
