include <bits/stdc++.h>

using namespace std;

int main()
{
string s;
getline(cin, s);
for(int i = 0; i < s.length(); i++){
if(islower(s[i])) s[i] = toupper(s[i]);
else if(isupper(s[i])) s[i] = tolower(s[i]);
}
cout << s;
return 0;
}