#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
void Say(bool say, string a = "Yes", string b = "No"){cout << (say ? a : b) << endl;};

int main(){

    string s;
    cin >> s;
    for(ll i = 0; i < s.size(); i++){
        if('A' <= s[i] && s[i] <= 'Z'){
            s[i] -= 'A';
            s[i] += 'a';
        }
    else{
            s[i] -= 'a';
            s[i] += 'A';
        }
    }
    cout << s << endl;

    return 0;
}