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 a = 0;
    a = reg & 1U;
    for (int i = 1; i < 32; i++)
    {
        a |= ( reg >> i ) & (1U << i);
    }
    return a;
}

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

Solving Approach