#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
// Your code here
volatile char i, idx = 0;
uint32_t ans = 0;
for(i=0;i<32;i=i+2){
if(reg & (1<<i)){
ans |= (1<<idx);
}
idx++;
}
return ans;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}