MOD = 10**9 + 7

N, K = map(int, input().split())

inv2 = pow(2, MOD-2, MOD)

# Compute term1: K*(K+3)/2 mod MOD
k_mod = K % MOD
k_plus_3_mod = (K + 3) % MOD
term1 = (k_mod * k_plus_3_mod) % MOD
term1 = (term1 * inv2) % MOD

# Compute term2: K*(K+1)/2 mod MOD
k_plus_1_mod = (K + 1) % MOD
term2 = (k_mod * k_plus_1_mod) % MOD
term2 = (term2 * inv2) % MOD

# Compute (term1^N - term2^N) mod MOD
term1_pow = pow(term1, N, MOD)
term2_pow = pow(term2, N, MOD)

ans = (term1_pow - term2_pow) % MOD

print(ans)