#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

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

using namespace std;

int main()
{
    string s;
    cin >> s;

    rep(i,s.size()) {
        if('a' <= s[i] && s[i] <= 'z') {
            s[i] = 'A' + (s[i] - 'a');
        } else if('A' <= s[i] && s[i] <= 'Z') {
            s[i] = 'a' + (s[i] - 'A');
        }
    }

    cout << s << endl;

	return 0;
}