Extract Even Bits Only from 32-bit Register

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

uint32_t extract_even_bits(uint32_t reg) {
  uint32_t rez=0;
  for(int i=0;i<16;i++)
  {
    if(reg & (1u<< (2*i)))
    rez=rez|(1u<<i);
  }
    return rez;
}

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