Since Grisha behaved well last year, at New Year's Eve he was visited by Ded Moroz who brought an enormous bag of gifts with him! The bag contains n sweet candies from the good ol' bakery, each labeled from 1 to n corresponding to its tastiness. No two candies have the same tastiness.

The choice of candies has a direct effect on Grisha's happiness. One can assume that he should take the tastiest ones — but no, the holiday magic turns things upside down. It is the xor-sum of tastinesses that matters, not the ordinary sum!

A xor-sum of a sequence of integers a1, a2, ..., am is defined as the bitwise XOR of all its elements: <image>, here <image> denotes the bitwise XOR operation; more about bitwise XOR can be found [here.](https://en.wikipedia.org/wiki/Bitwise_operation#XOR)

Ded Moroz warned Grisha he has more houses to visit, so Grisha can take no more than k candies from the bag. Help Grisha determine the largest xor-sum (largest xor-sum means maximum happiness!) he can obtain.

Input

The sole string contains two integers n and k (1 ≤ k ≤ n ≤ 1018).

Output

Output one number — the largest possible xor-sum.

Examples

Input

4 3


Output

7


Input

6 6


Output

7

Note

In the first sample case, one optimal answer is 1, 2 and 4, giving the xor-sum of 7.

In the second sample case, one can, for example, take all six candies and obtain the xor-sum of 7.
# n items, ordered, unique, 1..n

# find max xor, of  <= k out of n elems

n, k = map(int, input().strip().split())

#note: find largest power of 2  <= n, xor sum max is number of leading digits
# edit: largest power may contain freebies, hence, set ints directly
"""
largest_power = list(map(int, bin(n)[2:]))
#print(largest_power)

for i, v in enumerate(largest_power):
    if not v and k > 0:
        largest_power[i] = 1
        k -= 1

#print(largest_power)

sout = int("".join(map(str, largest_power)), 2)
print(sout)

# edit 2: given largest power, if k at least 2, all lower ones can be derived

"""

largest_power = bin(n)[2:]
#print(largest_power)
cur = int(largest_power, 2)
best = str((2 << len(largest_power) - 1) - 1)
print(cur if k == 1 else best)

"""
k = min(k, largest_power)

#print('k', k)
num = (1 << k) - 1
#print(num)

rest = largest_power - k

print(num << rest)
"""