#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <utility>

using namespace std;

int main(void){

    string s;
    cin >> s;
    int n = s.size();
    for(int i = 0; i < n; i++){
        if(s[i] >= 'A' && s[i] <= 'Z') s[i] += 0x20;
        else s[i] -= 0x20;
    }

    cout << s << endl;

    return 0;
}