#include <bits/stdc++.h>
using namespace std;

#include  <ext/pb_ds/assoc_container.hpp>
#include  <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define pb push_back
#define x first
#define y second
#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)

typedef long long ll;
typedef double db;
typedef long double LD;
typedef pair<int, int> pii;
typedef pair<db, db> pdd;
typedef pair<ll, ll> pll;

string ful = "";

void pre()
{
	for (char c = '0'; c <= '9'; c++)
		ful += c;
	for (char c = 'A'; c <= 'Z'; c++)
		ful += c;
	for (char c = 'a'; c <= 'z'; c++)
		ful += c;
}

string ask(const string& str)
{
	cout << str << endl;
	string resp;
	cin >> resp;
	return resp;
}

int solve(int b)
{
	string alf = ful.substr(0, b);
	int d;
	cin >> d;
	string bad(d, '=');
	vector<int> L(d, 0), R(d, b - 1);
	while (1)
	{
		string str = "";
		FOR (i, 0, d)
		{
			int mid = (L[i] + R[i]) / 2;
			str += alf[mid];
		}
		string resp = ask(str);
		if (resp == "correct")
			return 0;
		if (resp == bad || sz(resp) != d || L == R)
		{
			str = "cheater";
			resp = ask(str);
			assert(resp == "correct");
			return 0;
		}
		
		FOR (i, 0, d)
		{
			int mid = (L[i] + R[i]) / 2;
			if (resp[i] == '=')
			{
				L[i] = R[i] = mid;
			}
			else if (resp[i] == '+')
			{
				if (mid == b - 1 || L[i] == R[i])
				{
					str = "cheater";
					resp = ask(str);
					assert(resp == "correct");
					return 0;
				}
				L[i] = mid + 1;
			}
			else if (resp[i] == '-')
			{
				if (mid == 0 || L[i] == R[i])
				{
					str = "cheater";
					resp = ask(str);
					assert(resp == "correct");
					return 0;
				}
				R[i] = mid - 1;
			}
			else
			{
				str = "cheater";
				resp = ask(str);
				assert(resp == "correct");
				return 0;
			}
		}
	}
	
	return 0;
}

int32_t main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	pre();
	int TET = 1e9;
	int base;
	cin >> base >> TET;
	for (int i = 1; i <= TET; i++)
	{
		if (solve(base))
		{
			break;
		}
		#ifdef ONPC
			cerr << "_____________________________\n";
		#endif
	}
	#ifdef ONPC
		cerr << "\nfinished in " << clock() * 1.0 / CLOCKS_PER_SEC << " sec\n";
	#endif
	return 0;
}