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

if N % 2 == 0:
    print(N * M)
    exit()

bin_M = bin(M)[2:]

ans = 0
lower = 0

for i in range(len(bin_M)):
    if int(bin_M[i]) == 0:
        ans += 2 ** (len(bin_M) - i - 1) * ((lower // 2) * 2)
    else:
        lower = min(lower + 1, N)
        ans += 2 ** (len(bin_M) - i - 1) * (N - 1)

print(ans)