22. Extract Even Bits Only from 32-bit Register

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

uint32_t extract_even_bits(uint32_t reg) {
reg&=0x55555555;
reg=(reg|(reg>>1))&0x33333333;
reg=(reg|(reg>>2))&0x0f0f0f0f;
reg=(reg|(reg>>4))&0x00ff00ff;
reg=(reg|(reg>>8))&0x0000ffff;
return reg;

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