L = int(input())
mod = 10 ** 9 + 7
store = []
for _ in range(L):
    p,e = map(int,input().split())
    store.append((p,e))
ans = 1
for p,e in store:
    up = p * (pow(p,e+1,mod)-1) - (p-1) * (e+1)
    up %= mod
    down = (p-1) ** 2
    down %= mod
    tmp =  up * pow(down,mod-2,mod) 
    ans *= tmp
    ans %= mod
print(ans)