#include <bits/stdc++.h>
using namespace std;
struct container {
int l, r;
bool operator < ( container c ) {
return l < c.l;
}
};
const int MAX_N = 1e6;
const int MOD = 1e9 + 7;
int n;
bool bipartit = true;
bool vis[MAX_N], side[MAX_N];
container containers[MAX_N];
void checkBipartit( int u ) {
vis[u] = true;
for ( int v = 0; v < u; v++ ) {
if ( !(containers[v].r > containers[u].l && containers[v].r < containers[u].r) )
continue;
if ( vis[v] ) {
if ( side[u] == side[v] )
bipartit = false;
} else {
side[v] = side[u] ^ 1;
checkBipartit( v );
}
}
for ( int v = u + 1; v < n; v++ ) {
if ( !(containers[u].r > containers[v].l && containers[u].r < containers[v].r) )
continue;
if ( vis[v] ) {
if ( side[u] == side[v] )
bipartit = false;
} else {
side[v] = side[u] ^ 1;
checkBipartit( v );
}
}
}
int main() {
cin >> n;
for ( int i = 0; i < n; i++ )
cin >> containers[i].l >> containers[i].r;
sort( containers, containers + n );
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;
}
