#pragma GCC optimize ("Ofast","unroll-loops")
#include <bits/stdc++.h>
#define pb push_back
#define eb emplace_back
#define MP make_pair
#define F first
#define S second
#define setpre(a) cout.precision(a),cout<<fixed;
#define ALL(a) a.begin(),a.end()
#define MEM(a,b) memset(a,b,sizeof a)
#define Tie ios::sync_with_stdio(0),cin.tie(0);
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<ld,ld> pdd;
struct datas {
int x, y;
bool operator<(const datas &a) {
return x < a.x;
}
};
vector<datas> ori;
vector<int> e[1000100];
int n, v[1000100], tv[1000100], sz[2000100], C[2000100];
int find(int a) {
if(C[a] != a)
return C[a] = find(C[a]);
return a;
}
void merge(int a, int b) {
a = find(a);
b = find(b);
if(a == b) return;
if(sz[a] < sz[b])
swap(a, b);
// if(a > b) swap(a, b);
sz[a] += sz[b];
C[b] = a;
}
map<int, int> m;
void merge_sort(int l, int r) {
m.clear();
for(int i = 0; i < n; i++) {
auto p = m.lower_bound(ori[v[i]].y);
if(p != m.begin()) {
p--;
if(ori[p -> S].y > ori[v[i]].x) {
e[p -> S].pb(v[i]);
e[v[i]].pb(p -> S);
merge(p -> S, v[i] + n);
merge(v[i], p -> S + n);
}
}
m[ori[v[i]].y] = v[i];
}
}
bitset<1000100> vis;
vector<int> lv, rv;
void dfs(int a, int c) {
vis[a] = 1;
if(c == 1)
lv.pb(a);
else
rv.pb(a);
for(int i : e[a])
if(!vis[i])
dfs(i, 3 - c);
}
bool f(int a, int b) {
return ori[a].x < ori[b].x;
}
int main() {Tie
cin >> n;
ori.resize(n);
for(int i = 0; i < n; i++)
cin >> ori[i].x >> ori[i].y;
for(int i = 0; i < n * 2; i++)
C[i] = i, sz[i] = 1;
for(int i = 0; i < n; i++)
v[i] = i;
sort(v, v + n, f);
merge_sort(0, n - 1);
for(int i = 0; i < n; i++) {
ori[i].x = n * 2 + 1 - ori[i].x;
ori[i].y = n * 2 + 1 - ori[i].y;
swap(ori[i].x, ori[i].y);
}
for(int i = 0; i < n; i++)
v[i] = i;
sort(v, v + n, f);
merge_sort(0, n - 1);
int ans = 1;
for(int i = 0; i < n; i++) {
if(vis[i]) continue;
lv.clear();
rv.clear();
dfs(i, 1);
sort(ALL(lv), f);
int mx = -1;
for(int i : lv) {
if(ori[i].y > mx && mx > ori[i].x) {
cout << "0\n";
return 0;
}
mx = max(mx, ori[i].y);
}
sort(ALL(rv), f);
mx = -1;
for(int i : rv) {
if(ori[i].y > mx && mx > ori[i].x) {
cout << "0\n";
return 0;
}
mx = max(mx, ori[i].y);
}
}
for(int i = 0; i < n; i++)
if(find(i) == find(i + n)) {
cout << "0\n";
return 0;
}
int tmp = 0;
for(int i = 0; i < 2 * n; i++)
if(find(i) == i)
tmp++;
tmp >>= 1;
for(int i = 0; i < tmp; i++)
ans = (ans << 1) % 1000000007;
cout << ans << '\n';
}
