#include <iostream>
#include <stdio.h>
using namespace std;

unsigned ChangeBits(unsigned, unsigned);

int main() {
    unsigned x = 0x6FFF, y = 0x00F0;
    printf("\n%#04X", ChangeBits(x,y)) ;
    return 0;
}

unsigned ChangeBits(unsigned x, unsigned y){
    unsigned rValue, mask;
    mask = (~((y & 0xAAAA) << 16)) >> 16;

    rValue = mask & x;
    return rValue;
}