Extract Even Bits Only from 32-bit Register

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

uint32_t extract_even_bits(uint32_t reg) {
    // Your code here
    int i=0;
    uint16_t res=0;
    int p=0;
    while(i<32){
        if(((1U<<i)&(reg))>0){
            res|=(1U<<p);
            p++;
        }
i+=2;
    }
    return res;
}

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