#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;

#define pb push_back

const ld pi = 3.14159265358979323846;
const ll INF = 1e18;

template<typename T>
T chmax(T a, T b) {
    return a > b ? a : b;
}

template<typename T>
T chmin(T a, T b) {
    return a > b ? b : a;
}

const int N = (int)1e5 + 1, M = N * 2;

void solve(int b) {
    int n;
    cin >> n;

    int t = floor(log(b)) + 2;

    string s = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    vector<int> l(n, 0), r(n, b - 1);

    while(1){
        string st = "";
        for(int i = 0; i < n; i++){
            st += s[l[i] + r[i] >> 1];
        }

        cout << st << endl;
        string q;
        cin >> q;

        int uwu = 0;
        for(int i = 0; i < q.size(); i++){
            if (q[i] == '='){
                uwu++;
            }
        }

        if(uwu == n){
            cout << "cheater" << endl;
            string q;
            cin >> q;
            return;
        }
        if(q == "correct"){
            return;
        }

        for(int i = 0; i < n; i++){
            if(q[i] == '+'){
                if(l[i] >= r[i]){
                    cout << "cheater" << endl;
                    string q;
                    cin >> q;
                    return;
                }
                l[i] = (l[i] + r[i] >> 1) + 1;
            }
            if(q[i] == '-'){
                if(l[i] >= r[i]){
                    cout << "cheater" << endl;
                    string q;
                    cin >> q;
                    return;
                }
                r[i] = (l[i] + r[i] >> 1) - 1;
            }
        }
    }
    cout << 114514 << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);

    int b;
    cin >> b;

    int t = 1;
    cin >> t;

    while (t--) {
        solve(b);
    }

    return 0;
}