#include <cstdio>
#include <vector>
using namespace std;

const int mod = 1e9 + 7;

int power(int a, int b) {
	int res = 1;
	while (b) {
		if (b & 1) res = res * 1ll * a % mod;
		a = a * 1ll * a % mod;
		b /= 2;
	}
	return res;
}

int main() {
	auto sum = [&](int q, int n) {
		int res = 0;
		int u = 1;
		for (int i = 0; i <= n; i++) {
			res = (res + u) % mod;
			u = u * 1ll * q % mod;
		}
		return res;
	};
	
	auto qsum = [&](int a, int q, int n) {
		int up = (1 - power(q, n) + mod) % mod;
		up = up * 1ll * a % mod;
		int div = power((1 - q + mod) % mod, mod - 2);
		return up * 1ll * div % mod;
	};
	
	int n;
	scanf("%d", &n);
	int ans = 1;
	for (int i = 0; i < n; i++) {
		int q, e;
		scanf("%d%d", &q, &e);
		/*
		int cur = 0;
		for (int j = 0; j <= e; j++) {
			cur = (cur + sum(q, j)) % mod;			
		}*/
		int up = (e + 1);
		up = (up - qsum(q, q, e + 1) + mod) % mod;
		// printf("up = %d\n", up);
		int div = power((1 - q + mod) % mod, mod - 2);
		int my = up * 1ll * div % mod;
		// printf("i = %d, cur = %d, expect = %d\n", i, my, cur);
		ans = ans * 1ll * my % mod;
	}
	printf("%d\n", ans);
	return 0;	
}