#include <stdio.h> 
#include <limits.h>
#include <inttypes.h>
 
int main(void) { 
  uint32_t x; 
  for(; scanf("%"PRIi32,&x) > 0;
       printf("%"PRIi32"\n",
       (x )*( ( ( x / (1 << 31) ) + 1 ) % 2 ) +
       (-x)*( ( ( x / (1 << 31) ) ) % 2 )   ) 
     ); 
  return 0; 
}