#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
#include <cmath>
#include <climits>
#include <iomanip>
#include <set>
#include <map>
using namespace std;
typedef long long ll;
int main(){
    string s;
    cin >> s;
    for(int i = 0;i < (int)s.size();i++){
        if(s[i] >= 'a')s[i] = (char)(s[i] - 'a' + 'A');
        else s[i] = (char)(s[i] - 'A' + 'a');
    }
    cout << s << endl;
}