char *upper_string (char *stroka)
 {
 	char *simvol_vivoda = stroka;
 	while (*stroka!=NULL)
 	{

 	if ((*stroka>='a') && (*stroka<='z'))
 	{
 		*stroka=*stroka -'a'+'A';

		stroka++;
 	}
 	return (simvol_vivoda);
 	}
 }