#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
// Your code here
uint32_t sum=0;int pos=0;
for(uint8_t i=0;i<32;i=i+2)
{
sum += ((reg >> i) &1U)<<pos;
pos++;
}
return sum;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}