#include<bits/stdc++.h>
using namespace std;

int main() {
	string s;
	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[i];
	}
	return 0;
}

/**************************************************************
	Problem: 1182
	User: linzihang
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2076 kb
****************************************************************/