#include <iostream>
#include <math.h>
#include <algorithm>
#include <functional>
#include <vector>
#include <typeinfo>
#include <climits>
#include <ctype.h>
#include <string>
using namespace std;
#define INIT cin.tie(0); ios::sync_with_stdio(false);
#define FOR(i, a, n) for (int i = a; i < n; i++)
#define REP(i, n) for(int i = 0; i < n; i++)

int main()
{

    INIT;

    string s;
    cin >> s;

    REP(i, s.size()){
        if(isupper(s[i])){
            s[i] = tolower(s[i]);
        }else{
            s[i] = toupper(s[i]);
        }
    }
    cout << s << endl;

    return 0;
}