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 retval = 0;
    int j = 0;
    for(int i = 0; i < 32; i++)
    {
        retval |= (reg & (1 << i)) >> j;
        i++;
        j++;
    }
    return retval;
}

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

Solving Approach