#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
uint32_t bit_mask = 0;
int pos = 0;
for(int i = 0; i < 32; i+= 2)
{
if(reg & (1 << i))
{
bit_mask |= (1 << pos);
pos++;
}
}
return bit_mask;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}