MOD = 10**9 + 7

n, k = map(int, input().split())

if n == 1:
    print(1 % MOD)
else:
    e1 = (k + 1) % (MOD - 1)
    a = pow(n, e1, MOD)
    
    e2 = k % (MOD - 1)
    b = pow(n - 1, e2, MOD)
    b = (n * b) % MOD
    
    ans = (a - b) % MOD
    print(ans if ans >= 0 else ans + MOD)