#include<cstdio>
#include <iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<vector>
#include<functional>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<numeric>

using namespace std;
typedef long long ll;
typedef pair<int, int> Pr;

string s;

int main()
{
	cin >> s;
	for (int i = 0; i < s.size(); i++) {
		if (isupper(s[i]))
			printf("%c",tolower(s[i]));
		else
			printf("%c", toupper(s[i]));
	}
	cout << endl;
	return 0;
}