#include "bits/stdc++.h"
using namespace std;

#define REP(i, n) for(int i=0; i<(n); i++)

int N,T;
signed main()
{
    string s;
    cin >> s;
    for (auto&& t : s) {
        if ('a' <= t && t <= 'z') cout << (char)(t + 'A' - 'a');
        if ('A' <= t && t <= 'Z') cout << (char)(t - ('A' - 'a'));
    }
    cout << endl;
    return 0;
}