#include <stdio.h>
#include <stdint.h>
int bit,pos,res;
uint32_t extract_even_bits(uint32_t reg) {
// Your code here
res=0,pos=0;
for(bit=0;bit<=31;bit+=2)
{
if(reg & (1<<bit))
{
res |=(1<<pos);
}
pos++;
}
return res;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}