#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll m = 1e9 + 7;
ll mpow(ll a, ll n) {
    ll ret = 1;
    while (n) {
        if (n % 2) {
            ret *= a;
            ret %= m;
        }
        n /= 2;
        a = (a * a) % m;
    }
    return ret;
}
int main () {
    int N;
    cin >> N;
    ll ans = 1;
    for (int i = 0; i < N; i ++) {
        ll p, e;
        cin >> p >> e;
        ll q = mpow(p, e + 1);
        q = (q + m - 1) % m;
        q = (q * mpow(p - 1, m - 2)) % m;
        q = (q * p) % m;
        q += (m - ((e + 1) % m));
        q %= m;
        q = (q * mpow(p - 1, m - 2)) % m;
        ans *= q;
        ans %= m;
    }
    cout << ans << endl;
}