#include <bits/stdc++.h>
using namespace std;
#ifdef ngu
#include "debug.h"
#else
#define debug(...) 42
#endif
const int N = 1e6 + 5, MOD = 1e9 + 7;
int n;
int lab[N], c[N];
array<int, 2> p[N], s[8 * N];
int get(int u) {
if (lab[u] < 0) {
return u;
}
int p = get(lab[u]);
c[u] ^= c[lab[u]];
return lab[u] = p;
}
bool unite(int u, int v, int x) {
int a = get(u);
int b = get(v);
x ^= c[u] ^ c[v];
if (a == b) {
return !x;
}
if (lab[a] > lab[b]) {
swap(a, b);
}
lab[b] = a;
c[b] = x;
return true;
}
void upd(array<int, 2> &x) {
if (x[1] == 0 || x[1] == 3) {
return;
}
int p = get(x[0]);
x[1] = (x[1] - 1) ^ c[x[0]];
x[1]++;
x[0] = p;
}
array<int, 2> operator + (array<int, 2> &u, array<int, 2> &v) {
upd(u);
upd(v);
if (u[0] == 0 || v[0] == 0) {
return max(u, v);
}
if (u[0] == v[0] && u[1] && v[1]) {
return {u[0], u[1] | v[1]};
}
return {MOD, 0};
}
void upd(int i, int x) {
int id = 1, l = 1, r = 2 * n;
while (l != r) {
int md = (l + r) / 2;
id *= 2;
if (i <= md) {
r = md;
} else {
l = md + 1;
id += 1;
}
}
s[id] = {x, 1};
if (x == 2) {
upd(s[id]);
}
while (id > 1) {
id /= 2;
s[id] = s[id * 2] + s[id * 2 + 1];
}
}
void unite(array<int, 2> &x, int i) {
if (x[1] == 3 || !unite(x[0], i, 2 - x[1])) {
cout << 0;
exit(0);
}
upd(x);
}
void mrg(int u, int v, int i, int id = 1, int l = 1, int r = 2 * n) {
if (s[id][0] == 0) {
return;
}
if (u <= l && r <= v && s[id][1]) {
unite(s[id], i);
return;
}
int md = (l + r) / 2;
if (u <= md) {
mrg(u, v, i, id * 2, l, md);
}
if (md < v) {
mrg(u, v, i, id * 2 + 1, md + 1, r);
}
s[id] = s[id * 2] + s[id * 2 + 1];
}
auto main() -> int {
ios::sync_with_stdio(false);
cin.tie(0);
#ifdef ngu
freopen("test.inp", "r", stdin);
freopen("test.out", "w", stdout);
#endif
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> p[i][0] >> p[i][1];
}
fill(lab + 1, lab + n + 1, -1);
sort(p + 1, p + n + 1);
for (int i = 1; i <= n; ++i) {
auto [l, r] = p[i];
mrg(l, r, i);
upd(r, i);
}
int res = 1;
for (int i = 1; i <= n; ++i) {
if (lab[i] < 0) {
res = 1LL * res * 2 % MOD;
}
}
cout << res;
}
