#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 1000005;
const int MAXN2 = 2000005;
const ll mod = 1e9 + 7;
vector<pair<int, int>> adj[MAXN];
int fw[MAXN2], p[MAXN], rnk[MAXN], clr[MAXN];
int N, N2;
void update(int x, int v){
for (; x <= N2; x += (x & -x)) fw[x] += v;
}
int query(int x){
int res = 0;
for (; x; x -= (x & -x)) res += fw[x];
return res;
}
int rquery(int l, int r){
return query(r) - query(l - 1);
}
void dfs(int x, int c){
clr[x] = c;
for (auto [nn, nc] : adj[x]){
if (clr[nn] == -1) dfs(nn, c != nc);
else if (clr[nn] != (c != nc)){
cout << 0; exit(0);
}
}
}
ll pwr(ll a, ll b){
ll res = 1;
for (; b; b >>= 1){
if (b & 1) res = res * a % mod;
a = a * a % mod;
}
return res;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> N; N2 = N << 1;
vector<pair<int, int>> vec(N);
for (int i = 0; i < N; i++){
int l, r; cin >> l >> r;
vec[i] = {r, l};
}
for (int i = 1; i <= N2; i++) update(i, 1);
sort(vec.begin(), vec.end());
vector<tuple<int, int, int>> st;
memset(p, -1, sizeof(p)); memset(clr, -1, sizeof(clr));
for (int i = 0; i < N; i++){
int l, r; tie(r, l) = vec[i];
update(l, -1); update(r, -1);
while (!st.empty()){
int pl, pr, pid; tie(pl, pr, pid) = st.back();
if (l < pl){
st.pop_back();
if (rquery(pl, pr) != 0){
adj[i].push_back({pid, 0}); adj[pid].push_back({i, 0});
}
}
else if (l < pr){
if (rquery(l, pr) != 0){
cout << 0; return 0;
}
adj[i].push_back({pid, 1}); adj[pid].push_back({i, 1}); break;
}
else break;
}
st.push_back({l, r, i});
}
int cc = 0;
for (int i = 0; i < N; i++)
if (clr[i] == -1){
dfs(i, 0); cc++;
}
cout << pwr(2, cc);
}
