#include "bits/stdc++.h"
const signed MOD = 1e9 + 7;
const signed mod = 998244353;
using namespace std;
#define all(x) x.begin(), x.end()
#define ld long double
#define ll long long
#define pb push_back
#define mp make_pair
#define co cout <<
#define S second
#define F first
const string p = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

int get(string s) {
    string ans;
    int i = 15;
    while (s[i] != ' ') ans += s[i], i++;
    return stoi(ans);
}

void solve() {
    string temp = "a", s;
    while (1) {
        co temp << endl;
        getline(cin, s);
        if (s == "ACCESS GRANTED") return;
        if (get(s) != 5) break;
        temp += 'a';
    }
    
    for (int i = 0; i < (int)temp.size(); i++) {
        int a, b;
        a = get(s);
        temp[i]++;
        co temp << endl;
        getline(cin, s);
        if (s == "ACCESS GRANTED") return;
        b = get(s);
        for (char c : p) {
            temp[i] = c;
            co temp << endl;
            getline(cin, s);
            if (s == "ACCESS GRANTED") return;
            if (get(s) > min(a, b)) break;
        }
    }
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    signed t = 1;
    // cin >> t;
    while (t--) solve();
}