#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
uint16_t result = 0;
for (int i = 0; i<16 ; i++){
if (reg >> (2*i) & 1){
result |= (1<<i) ;
}
}
return result;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}