#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <iostream>
#include <vector>
#include <algorithm>
#define ericxiao ios_base::sync_with_stdio(0);cin.tie(0);
using namespace std;
const long long int MOD = 1e9 + 7;
const int maxN = 2e6 + 326;
int N, A[maxN], B[maxN], col[maxN], isIn[maxN], arr[maxN];
inline long long int mpow(long long int b, int e){
long long int r = 1;
for(int i = 0; i < 32; i++){
if((e >> i) & 1) r = r * b % MOD;
b = b * b % MOD;
}
return r;
}
struct Query{
int l, r, id;
Query(){}
Query(int l, int r, int id): l(l), r(r), id(id){}
};
vector<Query> ques;
bool has[maxN << 2][2];
vector<int> adj[maxN], seg[maxN << 2];
void query(int id, int l, int r, int p, int u){
for(int v : seg[id]){
adj[u].push_back(v);
adj[v].push_back(u);
}
if(seg[id].size() > 1){
seg[id].erase(seg[id].begin() + 1, seg[id].end());
}
if(l + 1 == r) return;
int m = (l + r) / 2;
if(p < m) query(2 * id + 1, l, m, p, u);
else query(2 * id + 2, m, r, p, u);
}
void modify(int id, int l, int r, int ql, int qr, int u){
if(l >= qr || ql >= r) return;
if(ql <= l && r <= qr){
seg[id].push_back(u);
return;
}
int m = (l + r) / 2;
modify(2 * id + 1, l, m, ql, qr, u);
modify(2 * id + 2, m, r, ql, qr, u);
}
void dfs(int now, int c = 0){
col[now] = c;
for(int v : adj[now]) if(col[v] == -1){
dfs(v, c ^ 1);
}
}
bool query2(int id, int l, int r, int p, int c){
if(has[id][c]) return false;
if(l + 1 == r) return true;
int m = (l + r) / 2;
if(p < m) return query2(2 * id + 1, l, m, p, c);
else return query2(2 * id + 2, m, r, p, c);
}
void modify2(int id, int l, int r, int ql, int qr, int c){
if(l >= qr || ql >= r) return;
if(ql <= l && r <= qr){
has[id][c] = 1;
return;
}
int m = (l + r) / 2;
modify2(2 * id + 1, l, m, ql, qr, c);
modify2(2 * id + 2, m, r, ql, qr, c);
}
inline int isValid(){
int cnt = 0;
fill(col, col + N + 1, -1);
/*
cout << "Conn: " << endl;
for(int i = 1; i <= N; i++){
cout << "u = " << i << ": "; for(int v : adj[i]) cout << v << ", "; cout << endl;
}
*/
for(int i = 1; i <= N; i++) if(col[i] == -1){
cnt++;
dfs(i);
}
//for(int i = 1; i <= N; i++) cout << "col[" << i << "] = " << col[i] << endl;
//cout << "cnt = " << cnt << endl;
for(auto [l, r, id] : ques){
if(!query2(0, 1, 2 * N + 1, l, col[id])) return -1;
modify2(0, 1, 2 * N + 1, l, r + 1, col[id]);
}
return cnt;
}
int main(){
ericxiao;
cin >> N;
for(int i = 1; i <= N; i++){
cin >> A[i] >> B[i];
arr[A[i]] = arr[B[i]] = i;
ques.emplace_back(A[i], B[i], i);
}
sort(ques.begin(), ques.end(), [](const Query &a, const Query &b){
return a.r < b.r;
});
for(auto [l, r, id] : ques){
query(0, 1, 2 * N + 1, l, id);
modify(0, 1, 2 * N + 1, l, r + 1, id);
}
int res = isValid();
if(res == -1){
cout << 0 << endl;
} else cout << mpow(2LL, res) << endl;
}
