#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  string s;
  cin >> s;

  for (char &c: s) {
    if (islower(c)) c = toupper(c);
    else c = tolower(c);
  }

  cout << s << endl;
  
  return 0;
}