//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <map>
#include <set>
#include <stack>
#define ll long long
#define maxn 1000005
#define mod 1000000007
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
struct obj{
int l, r, id;
obj() {
l = 0, r = 0, id = 0;
}
obj(int a, int b, int c) {
l = a, r = b, id = c;
}
};
obj a[maxn];
int ma[maxn];
inline bool cmp1(obj x, obj y) {
return x.l < y.l;
}
inline bool cmp2(obj x, obj y) {
return x.r > y.r;
}
int bit[2 * maxn];
void modify(int ind, int val) {
for (;ind < 2 * maxn;ind += ind & (-ind)) bit[ind] = max(bit[ind], val);
}
int query(int ind) {
int ret = 0;
for (;ind > 0;ind -= ind & (-ind)) ret = max(ret, bit[ind]);
return ret;
}
stack<obj> stk;
int par[maxn];
int find(int x) {
return x == par[x] ? x : par[x] = find(par[x]);
}
int main() {
ios_base::sync_with_stdio(0);cin.tie(0);
int n;
cin >> n;
for (int i = 0;i < n;i++) cin >> a[i].l >> a[i].r, a[i].id = i, par[i] = i;
sort(a, a + n, cmp1);
int poss = 1;
for (int i = 0;i < n;i++) {
ma[a[i].id] = query(a[i].r);
//cout << a[i].l << " " << a[i].r << " " << ma[a[i].id] << endl;
modify(a[i].r, a[i].r);
}
for (int i = 0;i < 2 * maxn;i++) bit[i] = 2 * maxn - 2 * n - 1;
sort(a, a + n, cmp2);
for (int i = 0;i < n;i++) {
//cout << a[i].l << " " << a[i].r << endl;
int val = query(2 * maxn - a[i].l);
if (2 * maxn - val < ma[a[i].id]) {
poss = 0;
break;
}
modify(2 * maxn - a[i].l, 2 * maxn - a[i].l);
}
if (poss) {
reverse(a, a + n);
int ans = n;
for (int ti = 0;ti < 2;ti++) {
for (int i = 0;i < n;i++) {
while (stk.size() && a[i].l < stk.top().l) stk.pop();
if (stk.size() && stk.top().r > a[i].l) {
if (find(a[i].id) != find(stk.top().id)) {
//cout << a[i].id << " " << stk.top().id << endl;
par[find(a[i].id)] = find(stk.top().id);
ans--;
}
}
stk.push(a[i]);
}
for (int i = 0;i < n;i++) {
a[i].l = 2 * maxn - a[i].l, a[i].r = 2 * maxn - a[i].r, swap(a[i].l, a[i].r);
}
reverse(a, a + n);
}
ll out = 1;
for (int i = 0;i < ans;i++) out = out * 2 % mod;
cout << out << "\n";
} else {
cout << 0 << "\n";
}
}
/*
4
1 3
2 5
4 8
6 7
3
1 4
2 5
3 6
5
1 4
2 10
6 9
7 8
3 5
8
1 15
2 5
3 8
4 6
14 16
7 9
10 13
11 12
5
2 5
4 7
6 8
1 9
3 10
*/
