#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
using pii = pair<int, int>;
pii P[2002];
const int mod = 1e9 + 7;
int mp(int x, int a) {
if (a == 0) return 1;
int ret = mp(x, a >> 1);
if (a & 1) return 1ll * ret * ret % mod * x % mod;
return 1ll * ret * ret % mod;
}
bool vis[2002], C[2002];
vector<int> edge[2002];
bool dfs(int x) {
vis[x] = 1;
for (auto i : edge[x]) {
if (vis[i]) {
if (C[x] == C[i]) return 1;
continue;
}
C[i] = C[x] ^ 1;
if (dfs(i)) return 1;
}
return 0;
}
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int N; cin >> N;
for (int i = 0; i < N; ++i) {
int x, y; cin >> x >> y;
P[i] = {x, y};
}
sort(P, P + N);
for (int i = 0; i < N; ++i) {
for (int j = i + 1; j < N; ++j) {
if (P[j].ff < P[i].ss && P[i].ss < P[j].ss) edge[i].push_back(j), edge[j].push_back(i);
}
}
int cnt = 0;
for (int i = 0; i < N; ++i) {
if (vis[i]) continue;
if (dfs(i)) return !printf("0");
cnt++;
}
printf("%d", mp(2, cnt));
return 0;
}
