#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <string>
#include <vector>
#include <cmath>
#include <set>
#include <map>
using namespace std;
using ll = long long;

int main(void)
{
  string S, R;
  cin >> S;
  int Upper = 90, Lower = 97;
  for (int i = 0; i < S.size(); i++)
  {
    if (isupper(S.at(i)))
    {
      R += tolower(S.at(i));
    }
    else
    {
      R += toupper(S.at(i));
    }
    /*
    if (S.at(i) <= Upper)
    {
      R += (S.at(i) + 32);
    }
    else
    {
      R += (S.at(i) - 32);
    }
    */
  }
  cout << R << endl;
  return 0;
}