#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <string>

void ConvertUL(char *str)
{
  for(int i=0;;i++){    
    if (str[i] == '\0'){
      break;
    }
    
    if (isupper(str[i])){
      printf("%c",tolower(str[i]));
    }else if (islower(str[i])){
      printf("%c",toupper(str[i]));
    }else{
      printf("%c",str[i]);
    }
  }
  printf("\n");
}

int main(void)
{
  char password[100];
  scanf("%s",password);
  ConvertUL(password);
  return 0;
}