#include <stdio.h>

/*  Program zamienia male litery na duze a duze na male */

int main()
{
   char a;

   while((a=getchar()) != EOF) 
   {
      if ( a >= 'a' && a <= 'z' ) a = a - ('a' - 'A');
      else if ( a >= 'A' && a <= 'Z' ) a = a + ('a' - 'A');
         
		putchar(a);
   }

   return 0;
}