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