from re import A


l = int(input())
mod = 10**9+7
ans = 1
for i in range(l):
    p,e = map(int,input().split())
    rp = pow(p-1,mod-2,mod)
    a = p*(pow(p,e+1,mod)-1)%mod*rp%mod
    a -= (e+1)
    a %= mod
    a *= rp
    ans *= a
    ans %= mod
print(ans)