#include <stdio.h>

const int Mod = 1000000007;

long long div_mod(long long x, long long y, long long z)
{
	if (x % y == 0) return x / y;
	else return (div_mod((1 + x / y) * y - x, (z % y), y) * z + x) / y;
}

long long pow_mod(int n, long long k)
{
	long long N, ans = 1;
	for (N = n; k > 0; k >>= 1, N = N * N % Mod) if (k & 1) ans = ans * N % Mod;
	return ans;
}

int main()
{
	int i, L, P[200001], e[200001];
	scanf("%d", &L);
	for (i = 1; i <= L; i++) scanf("%d %d", &(P[i]), &(e[i]));
	
	long long ans = 1;
	for (i = 1; i <= L; i++) ans = ans * (((e[i] + 1) * div_mod(pow_mod(P[i], e[i] + 1) - 1, P[i] - 1, Mod) + div_mod(pow_mod(P[i], e[i]) - 1, pow_mod((P[i] - 1), 2), Mod) * P[i] % Mod + Mod - div_mod(e[i] * pow_mod(P[i], e[i] + 1) % Mod, P[i] - 1, Mod)) % Mod) % Mod;
	printf("%lld\n", ans);
	fflush(stdout);
	return 0;
}