#include <iostream>
using namespace std;
int main(){
    string s;
    getline(cin,s);
    for(int i=0;i<=s.size();i++){
        if(s[i]>='a'&&s[i]<='z'){
            s[i]=s[i]-32;
        }
        else if(s[i]>='A'&&s[i]<='Z'){
            s[i]=s[i]+32;
        }
    }
    cout<<s;
    return 0;
}
/**************************************************************
	Problem: 1182
	User: wengsihan
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2076 kb
****************************************************************/