#include <bits/stdc++.h>
#define fastIO (cin.tie(0), cout.tie(0), ios::sync_with_stdio(false))
#define precise(i) fixed << setprecision(i)
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;

char toggle(char ch) {
  if ('a' <= ch && ch <= 'z') {
    return (char)(ch - 32);
  } else {
    return (char)(ch + 32);
  }
}

int main() {
  fastIO;
  string s;
  cin >> s;

  for (const auto ch : s) {
    cout << toggle(ch);
  }
  cout << '\n';
  return 0;
}