22. Extract Even Bits Only from 32-bit Register

#include <stdio.h>
#include <stdint.h>

uint32_t extract_even_bits(uint32_t reg)
{
    uint32_t result;

    for(int i = 0; i < 16; i ++)
    {
        if(reg & (1 << (2*i)))
        {
            result |= (1 << i);
        }
    }
    
    return result;
}

int main() {
    uint32_t reg;
    scanf("%u", &reg);
    printf("%u", extract_even_bits(reg));
    return 0;
}