MOD = 10 ** 9 + 7
n, k = map(int, input().split())
a = 1
b = 0
for i in range(k):
    a, b = ((n + 1) * a + (n - 1) * 2 * b) % MOD, (a + (n - 1) * 2 * b) % MOD
print(a)