# include <iostream>
# include <algorithm>
# include <vector>
# include <string>
# include <set>
# include <map>
# include <cmath>
# include <iomanip>
# include <functional>
# include <utility>
# include <stack>
# include <queue>
# include <list>
# include <bitset>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
constexpr long long MOD = 1000000000 + 7;
constexpr long long INF = 1000000000;
const double PI = acos(-1);



int main() {
	string s;
	cin >> s;
	for (int i = 0; i < s.size(); i++) {
		if (isupper(s[i])) {
			cout << char(tolower(s[i]));
		}
		else {
			cout << char(toupper(s[i]));
		}
	}
	cout << endl;
}