#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
uint16_t result = 0;
int i;
int k = 0;
for(i = 0; i <= 30; i+=2){
if(reg & (1 << i)){
result |= (1<<k);
k++;
}else{
k++;
}
}
return result;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}