#include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <iomanip>
#include <algorithm>
#include <map>
using namespace std;
using ll = long long;
constexpr ll M = 1e9+7;

int main() {
    map<char, char> m;
    for(int i=0; i<26; ++i) {
        m['a'+i] = 'A'+i;
        m['A'+i] = 'a'+i;
    }
    string s;
    cin >> s;
    for(int i=0; i<s.size(); ++i) {
        cout << m[s[i]];
    }
    cout << endl;
}