Extract Even Bits Only from 32-bit Register

Code

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

uint32_t extract_even_bits(uint32_t reg) {
    unsigned int sum = 0;
    for(int i = 30; i>=0 ; i-=2)
    {
        sum +=((reg>>i)&1);
        if(i>=2)
        sum = (sum<<1);
    }
    return sum;
}

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

Solving Approach