import numpy as np

N = int(input())
K = int(input())

dp_taro = np.zeros(6 * N + 1, dtype=float)
dp_taro[0] = 1
for _ in range(N - K):
    new_dp = np.zeros_like(dp_taro)
    for i in range(1, 7):
        new_dp[i:] += dp_taro[:-i]
    dp_taro = new_dp / 6
for _ in range(K):
    new_dp = np.zeros_like(dp_taro)
    for i in range(4, 7):
        new_dp[i:] += 2 * dp_taro[:-i]
    dp_taro = new_dp / 6

dp_jiro = np.zeros_like(dp_taro, dtype=float)
dp_jiro[0] = 1
for _ in range(N):
    new_dp = np.zeros_like(dp_taro)
    for i in range(1, 7):
        new_dp[i:] += dp_jiro[:-i]
    dp_jiro = new_dp / 6

res = dp_taro[:, None] * dp_jiro[None, :]
print(np.tril(res, k=-1).sum())