#include <bits/stdc++.h>
using namespace std;
#define finish(x) return cout << x << endl, 0
#define ll long long
const int N = 2000001;
int n, tree[4 * N], mod = 1e9 + 7;
vector <int> a;
void update(int l, int r, int node, int idx, int val){
if(r < l || r < idx || l > idx) return;
if(l == r){
tree[node] += val;
return;
}
int mid = (l + r) / 2;
update(l, mid, 2 * node, idx, val);
update(mid + 1, r, 2 * node + 1, idx, val);
tree[node] = max(tree[2 * node], tree[2 * node + 1]);
}
int query(int l, int r, int node, int s, int e){
if(r < l || r < s || l > e) return -1e9;
if(s <= l && r <= e) return tree[node];
int mid = (l + r) / 2;
return max(query(l, mid, 2 * node, s, e), query(mid + 1, r, 2 * node + 1, s, e));
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
a.resize(2 * n);
vector <int> l(n + 1), r(n + 1);
for(int i = 1 ; i <= n ; i++){
cin >> l[i] >> r[i];
l[i]--; r[i]--;
a[l[i]] = i;
a[r[i]] = -i;
}
int ans = 1;
for(auto &i : a){
if(i < 0){
int cur = -i;
for(int j = l[cur] ; j < r[cur] ; j++){
if(a[j] > 0 && r[a[j]] > r[cur]){
update(0, 2 * n, 1, r[a[j]], -1);
}
}
continue;
}
int b = query(0, 2 * n, 1, l[i], r[i]);
if(b >= 2) finish(0);
else if(b == 0){
ans *= 2;
if(ans >= mod) ans -= mod;
}
update(0, 2 * n, 1, r[i], b + 1);
}
cout << ans << endl;
}
