#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>
#include <sstream>
#include <map>
#include <queue>
#include <stack>

using namespace std;
 
const unsigned long long mod = 1000000000+7;

int main()
{
	string s;
	cin>>s;

	for(int i=0;i<s.size();i++){
		if(s[i]<='Z') s[i]=(s[i]-'A')+'a';
		else s[i]=(s[i]-'a')+'A';
	}
	cout<<s<<endl;

	return 0;
}