#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

int main() {
  string S; cin >> S;
  string T = "";
  for(int i = 0; i < (int)S.size(); i++){
    if('A' <= S[i] and S[i] <= 'Z'){
      T += S[i]-'A'+'a';
    }else{
      T += S[i]+'A'-'a';
    }
  }
  cout << T << endl;
}