#include <conio.h>
int __Messages=1;
#define MAIN_TESTING if(argc>1 && !strcmp(argv[1],"-n")) __Messages=0;
#define input_printf if(__Messages) printf
#define error_printf if(!__Messages) printf("invalid input data"); else printf
#define WAIT_ANY_KEY if(__Messages) {char c;fflush(stdin);scanf("%c",&c);}