#include<bits/stdc++.h>
using namespace std;
int main()
{
	char a;
    cin>>a;
    if(a>='a' && a<='z') cout<<char(a-32);
    else if(a>='A' && a<='Z') cout<<char(a+32);
    else cout<<a;
	return 0;
}

#include<bits/stdc++.h> using namespace std; int main() { char a; cin>>a; if(a>='a' && a<='z') cout<<char(a-32); else if(a>='A' && a<='Z') cout<<char(a+32); else cout<<a; return 0; }