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

using namespace std;

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

    for(int i=0; i<s.length(); i++){
        if(s[i]>='a' && s[i]<='z') s[i] += 'A'-'a';
        else if(s[i]>='A' && s[i]<='Z') s[i] += 'a'-'A';
    }
    cout << s << endl;

    return 0;
}