#include <bits/stdc++.h>
#include<limits.h>
#include<stdio.h>
#include<cstring>
#include<string>
using namespace  std;
typedef long long ll;
typedef long double ld;
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define pb push_back
#define mp make_pair
#define sz(a) a.size()
#define fi first
#define se second
#define rsz(a,n) a.resize(n)
#define test(t) ll t;cin>>t;while(t--)
#define forn(i,e) for(int i = 0; i < e; i++)
#define forsn(i,s,e) for(int i = s; i < e; i++)
#define rforn(i,s) for(int i = s; i >= 0; i--)
#define rforsn(i,s,e) for(int i = s; i >= e; i--)
#define fillv(a,k) memset(a,k,sizeof(a))
#define filla(a,k,n) memset(a,k,sizeof(a[0])*n)
#define leadzero(a) __builtin_clz(a) //count leading zeros
#define trailzero(a) __builtin_ctz(a) //count trailing zeros
#define bitcount(a) __builtin_popcount(a) // count set bits (add ll)
#define ln cout<<"\n"
#define sp cout<<" "
#define spaceprint(a,i,s,n) {forsn(i,s,n) { cout<<a[i]; sp;}}
#define lineprint(a,i,s,n) {forsn(i,s,n) {cout<<a[i]; ln;}}
#define maxe(a) *max_element(a.begin(),a.end())
#define maxi(a) max_element(a.begin(),a.end())-a.begin()
#define mine(a) *min_element(a.begin(),a.end())
#define mini(a) min_element(a.begin(),a.end())-a.begin()
#define all(c) c.begin(),c.end()
#define trav(container, it) for(typeof(container.begin()) it = container.begin(); it != container.end(); it++)
#define present(container, element) (container.find(element) != container.end())
#define cpresent(container, element)  (find(all(container),element) != container.end())// check the presence of element
//copy(from_begin, from_end, to_begin); copy function
typedef unsigned long long int ull;
typedef long double ld;
typedef pair<ll,ll> p64;
typedef pair<int,int> p32;
typedef pair<int,p32> p96;
typedef vector<ll> v64;
typedef vector<string> vs;
typedef vector<int> v32;
typedef vector<v32> vv32;
typedef vector<v64> vv64;
typedef vector<p32> vp32;
typedef vector<p64> vp64;
typedef vector<vp32> vvp32;
typedef map<int,int> m32;
const int LIM = 1e5+5, MOD = 1e9+7;
#define sumv(v) accumulate(all(v),ll(0))
#define productv(v) accumulate(all(v), ll(1), multiplies< ll >())
ll gcd(ll a, ll b) { if(b == 0) return a; return gcd(b, a % b); }
ll fastpowMOD(ll a, ll p,ll MOD){ if(p==0) return 1; ll z = fastpowMOD(a,p/2,MOD); z = (z*z)%MOD; if(p%2) z = (z*a)%MOD; return z; }
ll fastpow(ll a, ll p){ if(p==0) return 1; ll z = fastpow(a,p/2); z = (z*z); if(p%2) z = (z*a); return z; }
int main()
{
    ll t;
    cin>>t;
    ll k,f;
    cin>>f;
    for(k=1;k<=t;k++)
    {
        ll i;
        //ll c[6];
        string g="";
        v64 k[10];
        ll s=0;
        char a;
        for(i=0;i<119;i++)
        {
            cout<<5*i+1;
            cout<<endl;
            s++;
            cin>>a;
            k[a-'A'].pb(i);
        }
        ll t;
        for(i=0;i<5;i++)
        {
            if(k[i].size()==23)
            {
                t=i;
                break;
            }
        }
        g=g+char(t+'A');
        v64 v;
        for(i=0;i<k[t].size();i++)
        {
            v.pb(k[t][i]);
        }
        for(i=0;i<5;i++)
        {
            k[i].resize(0);
        }
        for(i=0;i<23;i++)
        {
            cout<<5*v[i]+2;
            s++;
            cout<<endl;
            //char a;
            cin>>a;
            k[a-'A'].pb(v[i]);
        }
        for(i=0;i<5;i++)
        {
            if(k[i].size()==5)
            {
                t=i;
                break;
            }
        }
        g+char(t+'A');
        v.resize(0);
        for(i=0;i<k[t].size();i++)
        {
            v.pb(k[t][i]);
        }
        for(i=0;i<5;i++)
        {
            k[i].resize(0);
        }
        for(i=0;i<5;i++)
        {
            cout<<5*v[i]+3;
            s++;
            cout<<endl;
            cin>>a;
            k[a-'A'].pb(v[i]);
        }
        for(i=0;i<5;i++)
        {
            if(k[i].size()==2)
            {
                t=i;
                break;
            }
        }
        g+char(t+'A');
        v.resize(0);
        for(i=0;i<k[t].size();i++)
        {
            v.pb(k[t][i]);
        }
        for(i=0;i<5;i++)
        {
            k[i].resize(0);
        }
        for(i=0;i<1;i++)
        {
            cout<<5*v[i]+4;
            s++;
            cout<<endl;
            //char a;
            cin>>a;
            k[a-'A'].pb(v[i]);
        }
        for(i=0;i<5;i++)
        {
            if(k[i].size()==1)
            {
                t=i;
                break;
            }
        }
        g+char(t+'A');
        v.resize(0);
        for(i=0;i<k[t].size();i++)
        {
            v.pb(k[t][i]);
        }
        for(i=0;i<5;i++)
        {
            k[i].resize(0);
        }
        ll y[6];
        for(i=0;i<g.size();i++)
        {
            y[g[i]-'A']++;
        }
        for(i=0;i<5;i++)
        {
            if(y[i]==0)
            {
                g+char(i+'A');
            }
        }
        //char a;
            for(i=0;i<f-s;i++)
            {
                cout<<5+4;
                cout<<endl;
                //char a;
                cin>>a;
            }
        cout<<g;
        cout<<endl;
        cin>>a;
    }
}