#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: xuanhua
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2076 kb
****************************************************************/