#include <iostream>
#include <vector>
#include <algorithm>
#include <cassert>
using ll = long long;
#define debug(x) #x << " = " << x << '\n'
const int NMAX = 1e6;
const int mod = 1e9 + 7;
struct Container {
int x, y;
bool operator < (const Container &other) const {
return x != other.x? x < other.x : y < other.y;
};
};
Container a[NMAX + 1];
std::vector<int> g[NMAX + 1];
bool vis[NMAX + 1];
int color[NMAX + 1];
bool bad = false;
void dfs(int u) {
vis[u] = true;
for (const auto &v : g[u]) {
if (!vis[v]) {
color[v] = (color[u] ^ 1);
dfs(v);
} else {
if (color[u] == color[v]) {
bad = true;
}
}
}
}
int main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
std::ios_base::sync_with_stdio(false);
std::cin.tie(0);
int n;
std::cin >> n;
for (int i = 1; i <= n; i++) {
std::cin >> a[i].x >> a[i].y;
}
std::sort(a + 1, a + n + 1);
for (int i = 1; i < n; i++) {
for (int j = i + 1; j <= n; j++) {
if (a[i].y > a[j].x && a[i].y < a[j].y) {
g[i].push_back(j);
g[j].push_back(i);
}
}
}
int answer = 1;
for (int i = 1; i <= n; i++) {
if (!vis[i]) {
color[i] = 0;
dfs(i);
if (bad) {
std::cout << 0;
return 0;
}
answer = (2 * answer) % mod;
}
}
std::cout << answer;
return 0;
}
