#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
// Your code here
int index; int val;
while (reg){
val|=((reg & 1u)<< index);
index++;
reg= reg>>2;
}
return val;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}