#include <iostream>
#include <string>
using namespace std;
string s;
int main(){
    cin>>s;
    for(int i=0;i<s.size();i++){
        if('a'<=s[i]&&s[i]<='z')cout<<char(s[i]-'a'+'A');
        else cout<<char(s[i]-'A'+'a');
    }
    cout<<endl;
    return 0;
}