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

signed main(){
  string S; cin >> S;
  for( int i = 0; i < S.size(); ++i )
    cout << ( char ) ( 'a' <= S[ i ] and S[ i ] <= 'z' ? S[ i ] - 'a' + 'A' : S[ i ] - 'A' + 'a' );
  cout << endl;
  return 0;
}