///Solutia 3

#include <iostream>
#include <cmath>


#include <iomanip>
using namespace std;

int main()
{
    long long n;
     long long  bit;
    long long  putere ;

    cin >> n >> bit;

    putere = pow(2,bit);
    if((n & putere) == 0)
        cout << n;
    else cout << n - putere;
    return 0;
}