/* -*- coding: utf-8 -*-
 *
 * 163.cc: No.163 cAPSlOCK - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

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

  for (int i = 0; i < s.size(); i++) {
    if (s[i] >= 'A' && s[i] <= 'Z') s[i] += 'a' - 'A';
    else if (s[i] >= 'a' && s[i] <= 'z') s[i] += 'A' - 'a';
  }

  cout << s << endl;
  return 0;
}