#include <iostream>
#include <string>
using namespace std;


int main(){
  int i = 0;
  string password;
  cin >> password;
  while(!(password[i] == '\0')){
    //cout << password[i] << endl;
    if (password[i]>='a' && password[i]<='z'){
      password[i] = toupper(password[i]);
    }else{
      password[i] = tolower(password[i]);
    }
    i++;
  }
  cout << password << endl;
}