#include <stdio.h>
#include <stdint.h>
uint32_t extract_even_bits(uint32_t reg) {
// Your code here
uint32_t ans = 0;
uint8_t iteration = 0;
while(reg != 0)
{
ans |= ((reg & 0x01)) << iteration;
reg = reg >> 2;
iteration++;
}
return ans;
}
int main() {
uint32_t reg;
scanf("%u", ®);
printf("%u", extract_even_bits(reg));
return 0;
}