#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <limits>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <complex>

using namespace std;

#define INF (INT_MAX/3)
#define PI (2*acos(0.0))
#define EPS (1e-8)

typedef long long ll;
typedef unsigned long long ull;

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

int main(){
  ios_base::sync_with_stdio(0);
  string s;
  cin >> s;
  trans(s);
  cout << s << endl;
  return 0;
}