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