MOD = 10 ** 9 + 7 N = 2000200 fact = [0 for _ in range(N)] invfact = [0 for _ in range(N)] fact[0] = 1 for i in range(1, N): fact[i] = fact[i - 1] * i % MOD invfact[N - 1] = pow(fact[N - 1], MOD - 2, MOD) for i in range(N - 2, -1, -1): invfact[i] = invfact[i + 1] * (i + 1) % MOD def nCk(n, k): if k < 0 or n < k: return 0 else: return (fact[n] * invfact[k] % MOD) * invfact[n - k] % MOD def nHk(n, k): return nCk(n + k - 1, k) n, m = map(int, input().split()) ans = 0 pm = 1 bi = [1] for _ in range(n): bi.append(bi[-1] * 2 % MOD) for k in range(n + 1): ans += nCk(n, k) * pm * pow(bi[n - k] - 1, m, MOD) ans %= MOD pm *= -1 print(ans)