import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
from functools import lru_cache

n, m = na()
# inf = float("inf")
# @lru_cache(maxsize=None)
# def solve(p, q):
#     if p < 0 or q < 0:
#         return -inf
#     if p == 0 and q == 0:
#         return 0
#     for i in range(2):
#         for j in range(2):
#             if i 

# print(bin(m))

if n % 2 == 0:
    print(m * n)
else:
    res = 0
    cnt = 0
    ans = 0
    for i in range(32, -1, -1):
        if m >> i & 1:
            cnt += 1
            ans += (n - 1 ) << i
            # print(i, n - 1)
        else:
            ans += (cnt//2) << (i + 1)
            # print(i, (cnt//2) * 2)
    print(ans)