#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
// Your code here
uint32_t ret = 0;
for(int i = 0;i<31;i=i+2){
ret |= (reg>>(i/2) )& (1<<(i/2));
}
return ret;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}