#include <iostream>
#include <sstream>
#include <math.h>
#include <stack>
#include <set>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <vector>
using namespace std;

#define INF (1 << 30)
#define INFLL (1LL << 60)

int main() {
	string str;
	cin >> str;
	for(int i = 0;i < str.size();i++){
		if(str[i] >= 'A' && str[i] <= 'Z') {
			str[i] += 32;
		}else if(str[i] >= 'a' && str[i] <= 'z'){
			str[i] -= 32;
		}
	}
	cout << str << endl;
	return 0;
}