#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 1e6;
const int MOD = 1e9 + 7;
bool vis[MAX_N], side[MAX_N];
int l[MAX_N], r[MAX_N];
vector<int> edges[MAX_N];
bool bipartit = true;
void checkBipartit( int u ) {
vis[u] = true;
for ( int v: edges[u] ) {
if ( vis[v] ) {
if ( side[u] == side[v] )
bipartit = false;
} else {
side[v] = side[u] ^ 1;
checkBipartit( v );
}
}
}
int main() {
int n;
cin >> n;
for ( int i = 0; i < n; i++ )
cin >> l[i] >> r[i];
for ( int i = 0; i < n; i++ ) {
for ( int j = i + 1; j < n; j++ ) {
if ( (l[i] <= l[j] && r[i] <= r[j] && r[i] >= l[j]) || (l[j] <= l[i] && r[j] <= r[i] && r[j] >= l[i]) ) {
edges[i].push_back( j );
edges[j].push_back( i );
}
}
}
int comp = 0;
for ( int u = 0; u < n; u++ ) {
if ( !vis[u] ) {
side[u] = 0;
checkBipartit( u );
comp++;
}
}
if ( bipartit ) {
int ans = 1;
for ( int i = 0; i < comp; i++ )
ans = ans * 2 % MOD;
cout << ans;
} else
cout << 0;
return 0;
}
