#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
unsigned int sum = 0;
for(int i = 30; i>=0 ; i-=2)
{
sum +=((reg>>i)&1);
if(i>=2)
sum = (sum<<1);
}
return sum;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}