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

int main() {
  string S;
  cin >> S;

  for (int i = 0; i < S.size(); i++) {
    if (isupper(S.at(i))) S.at(i) -= ('A' - 'a');
    else S.at(i) += ('A' - 'a');
  }

  cout << S << "\n";
}