#include <stdio.h>
#include <ctype.h>

/* by Entrance */

char *Buyuk(char *str)
{
	char *ret = str;
	
	while(*str != '\0')
	{
		if(islower(*str) != 0)
		{
		    *str = toupper(*str);
			 str++;
		}
		else{
			*str = tolower(*str);
		     str++;
		}
		
	}
	return ret;
}

int main() {
   
   char ent[1024];
   
   printf("Bir seyler yaziniz : \n");
   gets(ent);
   
   printf("%s",Buyuk(ent)); 
}