#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
const int N = 1e6 + 5, MD = 1e9 + 7;
int n;
int a[N], b[N], lab[2 * N], c[2 * N];
int get(int u) {
if (lab[u] < 0) {
return u;
}
int p = get(lab[u]);
c[u] ^= c[lab[u]];
lab[u] = p;
return p;
}
void mrg(int u, int v) {
int a = get(u), b = get(v);
int w = c[u] ^ c[v] ^ 1;
if (a == b) {
if (w) {
cout << 0;
exit(0);
}
} else {
lab[a] += lab[b];
lab[b] = a;
c[b] = w;
}
}
set<array<int, 2>> st;
set<int> cands;
void split(int l, int r, int p) {
st.erase({l, r});
auto it = cands.upper_bound(p);
st.insert({*it, r});
st.insert({l, *--it});
}
void add(int p) {
auto it = st.lower_bound({p + 1, 0});
if (it != st.begin()) {
--it;
auto [l, r] = *it;
if (r >= p) {
split(l, r, p);
}
}
lab[p] = -1;
cands.insert(p);
st.insert({p, p});
}
void add(int l, int r, int u) {
auto it = st.lower_bound({l, 0});
if (it != st.begin() && (*prev(it))[1] >= l) {
--it;
}
int L = MD, R = -MD;
for (; it != st.end() && (*it)[0] <= r; it = st.erase(it)) {
mrg(u, (*it)[0]);
L = min(L, (*it)[0]);
R = max(R, (*it)[1]);
}
if (L != MD) {
st.insert({L, R});
}
}
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> a[i] >> b[i];
}
vector<int> ord(n); iota(ord.begin(), ord.end(), 1);
sort(ord.begin(), ord.end(), [&](int i, int j) {
return a[i] < a[j];
});
for (int u : ord) {
add(b[u]);
add(a[u], b[u] - 1, b[u]);
}
int res = 1;
for (int i = 1; i <= 2 * n; ++i) {
if (lab[i] < 0) {
res = res * 2 % MD;
}
}
cout << res;
return 0;
}
