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
    uint32_t result = 0;
    for(int i = 0; i < 16; i++){
        uint32_t mask = (reg >> (2 * i)) & 1U;
        result |= mask << i;
    }
    return result;
}

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