#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <algorithm>
#include <random>
#include <iomanip>
#include <cassert>
#include <complex>
#include <functional>
using namespace std;
typedef long long ll;
const int md = 1e9 + 7;
void add(int &a, int b) {
a += b;
if (a >= md) a -= md;
}
int mul(int a, int b) {
return ((ll)a * b) % md;
}
int power(int a, ll b) {
int res = 1;
while (b > 0) {
if (b & 1) res = mul(res, a);
a = mul(a, a);
b >>= 1;
}
return res;
}
int inv(int a) {
return power(a, md - 2);
}
const int N = 2e3 + 7;
vector <int> g[N];
int col[N];
void dfs(int u) {
for (auto v : g[u]) {
if (col[v] == -1) {
col[v] = col[u] ^ 1;
dfs(v);
} else if (col[v] != (col[u] ^ 1)) {
cout << "0\n";
exit(0);
}
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
int n;
cin >> n;
vector <int> a(n), b(n);
for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
for (int i = 0; i < n; ++i) {
for (int j = 0; j < n; ++j) {
if (a[i] < a[j] && a[j] < b[i] && b[i] < b[j]) {
g[i].push_back(j);
g[j].push_back(i);
} else if (a[j] < a[i] && a[i] < b[j] && b[j] < b[i]) {
g[i].push_back(j);
g[j].push_back(i);
}
}
}
fill(col, col + n, -1);
int cmp = 0;
for (int i = 0; i < n; ++i) {
if (col[i] == -1) {
++cmp;
col[i] = 0;
dfs(i);
}
}
int ans = power(2, cmp);
cout << ans << '\n';
}
