#include <bits/stdc++.h>
#define maxn 1000005
#define fi first
#define se second
using namespace std;
using ii = pair<int, int>;
constexpr int mod = 1000000007;
int n;
map<int, int> rd;
set<int> ww, ll;
ii a[maxn];
void ins(const int &a, const int &b) {
auto it = rd.lower_bound(a);
if (it != rd.end() && it->se <= b) return;
it = rd.insert(it, {a, b});
it->se = b;
while (it != rd.begin() && prev(it)->se >= b) rd.erase(prev(it));
}
int nho[2*maxn];
int par[maxn], slt;
int find_set(int v) {
return par[v] < 0 ? v : par[v] = find_set(par[v]);
}
void union_set(int u, int v) {
u = find_set(u); v = find_set(v);
if (u == v) return;
if (par[u] < par[v]) swap(u, v);
--slt;
par[v] += par[u];
par[u] = v;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
cin >> n;
slt = n;
for (int i = 1; i <= n; i++) cin >> a[i].fi >> a[i].se;
sort(a + 1, a + n + 1);
for (int i = 1; i <= n; i++) {
par[i] = -1;
nho[a[i].fi] = nho[a[i].se] = i;
}
for (int i = 1; i <= n; i++) {
auto START = ww.lower_bound(a[i].fi), END = ww.lower_bound(a[i].se);
vector<int> vals;
for (auto it = START; it != END; it++) {
union_set(i, nho[*it]);
vals.emplace_back(*it);
}
for (int x : vals) ww.erase(x);
auto it = rd.lower_bound(a[i].fi);
if (it != rd.end() && it->se < a[i].se) {cout << 0; exit(0);}
ll.insert(a[i].se);
ww.insert(a[i].se);
auto ti = ll.lower_bound(a[i].se);
if (ti != ll.begin()) {
--ti;
ins(*ti, a[i].se);
if (*ti > a[i].fi) union_set(nho[*ti], i);
}
}
int ans = 1;
while (slt--) ans = ans * 2 % mod;
cout << ans;
}
