N, K = map(int, input().split()) mod = 10 ** 9 + 7 n = 202020 fact = [1] * (n + 1) invfact = [1] * (n + 1) for i in range(1, n): fact[i + 1] = ((i+1) * fact[i]) % mod invfact[n] = pow(fact[n], mod - 2, mod) for i in range(n - 1, -1, -1): invfact[i] = invfact[i + 1] * (i + 1) % mod def comb(n, r): if n < 0 or r < 0 or n - r < 0: return 0 return fact[n] * invfact[r] * invfact[n - r] % mod ans = 0 now = 1 for i in range(N): ans += comb(N, i) * now * pow(K, N - i, mod) ans %= mod now *= K * (K + 1)//2 now %= mod print(ans)