Extract Even Bits Only from 32-bit Register

Code

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

uint32_t extract_even_bits(uint32_t reg) {
    uint32_t res = 0;
    for(int i = 0; i <=15 ;i++){
        //mask size = 1, only extracting a field of size 1
        int temp = (reg >> 2*i) & 1;

    }
    return res;
}

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

Solving Approach