#include <algorithm>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;

typedef long long ll;

#define MOD 1000000007

int main() {
  string s;
  cin >> s;
  int n = s.size();
  for (int i = 0; i < n; ++i) {
    if (isupper(s[i])) {
      s[i] = tolower(s[i]);
    } else {
      s[i] = toupper(s[i]);
    }
  }
  cout << s << endl;
  return 0;
}