#include <bits/stdc++.h>
using namespace std;
int main(){
  string S;
  cin >> S;
  int N = S.size();
  for (int i = 0; i < N; i++){
    if (isupper(S[i])){
      cout << (char) tolower(S[i]);
    }
    if (islower(S[i])){
      cout << (char) toupper(S[i]);
    }
  }
  cout << endl;
}