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 out = 0 ; 
    while(reg > 0 )
    {
        out |= (reg & 1);
        reg >>=2;
        if(reg == 0)
        {
            break;
        }
        out <<=1 ; 
    }
    return out;
}

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

Solving Approach