#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
// Your code here
uint32_t result = 0;
while (reg != 0) {
result <<= 1;
result |= (reg&1);
reg >>= 2;
}
return result;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}