#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <utility>
#include <list>
#include <functional>
#include <queue>
#include <map>
#include <iterator>
#include <iomanip>
#include <complex>
#include <cctype>
using namespace std;

using ull = unsigned long long;
using ll = long long;


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

  for(auto&& x : s)
  {
    if(isupper(x))
    {
      x = tolower(x);
    }
    else
    {
      x = toupper(x);
    }
  }

  cout << s << endl;
}