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