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