#include<iostream>
#include<string>

using namespace std;

int main(){

  string S1;
  cin >> S1;


  for(int i = 0; i <S1.length();i++){
      if(isupper(S1[i]))
        S1[i] = tolower(S1[i]);
      else
        S1[i] = toupper(S1[i]);;
  }
  cout << S1 << endl;
    return 0;
}