#include <iostream>
#include <vector>
#include <algorithm>
#include <cctype>
#define P(x) cout <<x<<endl
using namespace std;

int main(){
    string str,ans;
    cin >> str;
    for(int i=0;i<str.size();i++){
        if(isupper(str[i])){
            ans += tolower(str[i]);
        }else{
            ans += toupper(str[i]);
        }
    }
    P(ans);
}