/* There's someone in my head but it's not me */
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<int, int> pii;
#define SZ(x) (int) x.size()
#define F first
#define S second
#define lc id << 1
#define rc lc | 1
const int N = 1e6 + 10, MOD = 1e9 + 7;
int al[N], ar[N], M[N], n; pii mx[N << 2], mn[N << 2];
void modify(int p, pii x, int id = 1, int l = 1, int r = n * 2 + 1) {
if (r - l < 2) {
mx[id] = mn[id] = x;
return;
}
int md = (l + r) >> 1;
if (p < md) modify(p, x, lc, l, md);
else modify(p, x, rc, md, r);
mx[id] = max(mx[lc], mx[rc]);
mn[id] = min(mn[lc], mn[rc]);
}
pair<pii, pii> get(int ql, int qr, int id = 1, int l = 1, int r = n * 2 + 1) {
if (qr <= l || r <= ql || ql >= qr) return {{-MOD, -MOD}, {MOD, MOD}};
if (ql <= l && r <= qr) return {mx[id], mn[id]};
int md = (l + r) >> 1;
pair<pii, pii> a = get(ql, qr, lc, l, md), b = get(ql, qr, rc, md, r);
return {max(a.F, b.F), min(a.S, b.S)};
}
void remove(int p, int id = 1, int l = 1, int r = 2 * n + 1) {
if (r - l < 2) {
mx[id] = {-MOD, -MOD}, mn[id] = {MOD, MOD};
return;
}
int md = (l + r) >> 1;
if (p < md) remove(p, lc, l, md);
else remove(p, rc, md, r);
mx[id] = max(mx[lc], mx[rc]);
mn[id] = min(mn[lc], mn[rc]);
}
int edge(int u, int v) {
if (al[u] > al[v]) swap(u, v);
return al[u] < al[v] && ar[u] < ar[v] && ar[u] > al[v];
}
void DFS(int v, int p) {
M[v] = 1, remove(al[v]), remove(ar[v]);
while (1) {
pair<pii, pii> x = get(al[v], ar[v]);
if (x.F.F > ar[v]) {
if (~p && edge(p, x.F.S)) { printf("0\n"); exit(0); }
DFS(x.F.S, v);
}
else if (x.S.F < al[v]) {
if (~p && edge(p, x.S.S)) { printf("0\n"); exit(0); }
DFS(x.S.S, v);
}
else break;
}
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++)
scanf("%d%d", &al[i], &ar[i]), modify(al[i], {ar[i], i}), modify(ar[i], {al[i], i});
int gc = 0;
for (int i = 1; i <= n; i++) {
if (!M[i]) DFS(i, -1), gc++;
}
int ret = 1;
for (; gc; gc--) ret = 2ll * ret % MOD;
printf("%d\n", ret);
return 0;
}
