#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    string s;
    cin >> s;
    rep(i, s.size()){
        if(s[i] < 91){
            s[i] += 32;
        }else{
            s[i] -= 32;
        }
    }
    cout << s << endl;
    return 0;
}