23 с конца

#https://inf-ege.sdamgia.ru/problem?id=78048
dp = [0] * 52
dp[51] = 1
for i in range(51, 17, -1):
    if i == 32:
        continue
    dp[i - 1] += dp[i]
    if i // 2 >= 17:
        dp[i // 2] += dp[i]
for i in range(17, 15, -1):
    dp[i - 1] += dp[i]
for i in range(15, 7, -1):
    dp[i - 1] += dp[i]
    if i // 2 >= 7:
        dp[i // 2] += dp[i]
print(dp[7])