3674. 唐纳德先生与 .DOC

#include <bits/stdc++.h>

using namespace std;

int main() {
    int T;
    cin >> T;
    while (T--) {
        string s;
        cin >> s;
        for (int i = 0; i < s.length() - 1; ++i) {
            if (s[i] == '.' && s[i + 1] == '.') {
                cout << 'C';
            } else {
                cout << 'D';
            }
        }
        cout << endl;
    }
    return 0;
}