#include <bits/stdc++.h>
using namespace std;
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define FOD(i, a, b) for(int i = a; i >= b; i--)
#define fi first
#define se second
#define ll long long
#define db double
#define ii pair<int,int>
#define pb push_back
#define MASK(i) (1LL << i)
#define sq(i) (1LL * (i) * (i))
#define task "task"
const ll INF = 1e18;
const int inf = 1e9;
const int N = 1e6 + 4;
const int mod = 1e9 + 7;
int mul(int a, int b) {
return 1LL * a * b % mod;
}
int n;
ii a[N];
struct Dsu {
int cc;
int root[N], sze[N], h[N];
void init() {
cc = n;
FOR(i, 1, n) {
h[i] = 0;
root[i] = i;
sze[i] = 1;
}
}
ii anc(int u) {
if(u == root[u]) return {u, 0};
ii tmp = anc(root[u]);
root[u] = tmp.fi;
h[u] += tmp.se;
return {root[u], h[u]};
}
bool join(int u, int v) {
ii ru = anc(u);
ii rv = anc(v);
if(ru.fi == rv.fi) {
if((ru.se + rv.se) % 2 == 0) return true;
return false;
}
cc--;
if(sze[ru.fi] < sze[rv.fi]) swap(ru, rv);
root[rv.fi] = ru.fi;
sze[ru.fi] += sze[rv.fi];
h[rv.fi] = (rv.se + ru.se + 1) % 2;
return false;
}
} dsu;
vector<int> cur;
int idx[2 * N];
struct Event {
int p, t, id;
bool operator < (const Event &b) const {
return p < b.p;
}
};
vector<Event> ev;
int binpow(int a, int b) {
if(b == 0) return 1;
int tmp = binpow(a, b / 2);
if(b & 1) return mul(mul(tmp, tmp), a);
return mul(tmp, tmp);
}
void solve() {
FOR(i, 1, n) {
ev.pb({a[i].fi, 0, i});
ev.pb({a[i].se, 1, i});
}
sort(ev.begin(), ev.end());
dsu.init();
for(auto x : ev) {
if(x.t == 0) cur.pb(x.p);
else {
vector<int>::iterator it = lower_bound(cur.begin(), cur.end(), a[x.id].fi);
int st = it - cur.begin() + 1;
for(; st < cur.size(); st++) {
if(dsu.join(idx[cur[st]], x.id)) {
cout << 0 << '\n';
return;
}
}
cur.erase(it);
}
}
cout << binpow(2, dsu.cc) << '\n';
}
signed main() {
if(fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
//freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int tc = 1;
// cin >> tc;
while(tc--) {
cin >> n;
FOR(i, 1, n) {
cin >> a[i].fi >> a[i].se;
idx[a[i].fi] = i;
}
solve();
}
}
