#include <bits/stdc++.h>
using namespace std;
using LL = long long;
const int MOD = (int)1e9 + 7;
const int NS = (int)2e5 + 4;
int N;
pair<int, int> a[NS];
pair<int, int> tree[NS * 4];
void upd(pair<int, int>&A, int B){
if(B < A.first){
A.second = A.first;
A.first = B;
}
else if(B < A.second){
A.second = B;
}
}
void push(int num, int s, int e, int pos, int val){
if(pos < s || pos > e){
return;
}
if(s == e){
upd(tree[num], val);
return;
}
push(num * 2, s, (s + e) / 2, pos, val);
push(num * 2 + 1, (s + e) / 2 + 1, e, pos, val);
tree[num] = tree[num * 2];
upd(tree[num], tree[num * 2 + 1].first);
upd(tree[num], tree[num * 2 + 1].second);
}
pair<int, int> get(int num, int s, int e, int fs, int fe){
if(fe < s || fs > e || fs > fe){
return {MOD, MOD};
}
if(s >= fs && e <= fe){
return tree[num];
}
pair<int, int> l = get(num * 2, s, (s + e) / 2, fs, fe);
pair<int, int> r = get(num * 2 + 1, (s + e) / 2 + 1, e, fs, fe);
upd(l, r.first), upd(l, r.second);
return l;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
for(int i = 0; i < NS * 4; ++i){
tree[i].first = tree[i].second = MOD;
}
cin >> N;
for(int i = 1; i <= N; ++i){
cin >> a[i].first >> a[i].second;
}
sort(a + 1, a + N + 1, [&](pair<int, int>&A, pair<int, int>&B){return A.second < B.second;});
int ans = 1;
for(int i = 1; i <= N; ++i){
pair<int, int> rv = get(1, 1, NS - 1, a[i].first + 1, a[i].second - 1);
if(rv.first < a[i].first && rv.second < a[i].first){
ans = 0; break;
}
if(rv.first > a[i].first){
ans = (ans * 2) % MOD;
}
push(1, 1, NS - 1, a[i].second, a[i].first);
}
cout << ans;
return 0;
}
