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