#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
typedef long long LL;

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