#include <bits/stdc++.h>
#define rep(i, ss, ee) for (int i = ss; i < ee; ++i)
using namespace std;

char inversionTopLow(char c) {
  char result;
  if (c - 'a' >= 0 and c - 'a' < 26) {
    result = toupper(c);
  } else {
    result = tolower(c);
  }
  return result;
}

int main() {
  string s;
  cin >> s;
  rep(i, 0, s.size()) { s[i] = inversionTopLow(s[i]); }
  cout << s << endl;
  getchar();
}