ESAd ATAb

//ALEX ENACHE

#include <vector>
#include <algorithm>

#include <math.h>
#include <iomanip>
#include <bitset>

#include <queue>
#include <deque>
#include <stack>
#include <string>

#include <map>
#include <unordered_map>
#include <set>
#include <unordered_map>

#include <random>
#include <time.h>
#include <assert.h>
#include <iostream>

using namespace std;

const int MAXN = 105;

int n;
int dif;
int eq;

int ans[MAXN];


int oposite(int i) {
    return n - i + 1;
}


void REVERSE() {
    for (int i = 1; i <= n / 2; i++) {
        swap(ans[i], ans[oposite(i)]);
    }
}

void XOR() {
    for (int i = 1; i <= n; i++) {
        ans[i] ^= 1;
    }
}


int changes() {

    int DIF, EQ;

    if (dif && eq) {

        cout << dif << endl;
        cin >> DIF;
        cout << eq << endl;
        cin >> EQ;

        if (DIF == ans[dif] && EQ == ans[eq]) {
            //ok
        }
        else if (DIF != ans[dif] && EQ == ans[eq]) {
            REVERSE();
        }
        else if (DIF == ans[dif] && EQ != ans[eq]) {
            REVERSE();
            XOR();
        }
        else if (DIF != ans[dif] && EQ != ans[eq]) {
            XOR();
        }

        return 8;
    }
    if (dif) {


        cout << dif << endl;
        cin >> DIF;

        if (DIF != ans[dif]) {
            REVERSE();
        }

        return 9;
    }
    if (eq) {

        cout << eq << endl;
        cin >> EQ;

        if (EQ != ans[eq]) {
            XOR();
        }

        return 9;
    }
    return 10;
}


void solve() {

    int pos = 1;

    dif = 0;
    eq = 0;

    while (pos <= oposite(pos)) {

        int moves = changes();

        while (moves >= 2 && pos <= oposite(pos)) {

            int op = oposite(pos);

            cout << pos << endl;
            cin >> ans[pos];


            cout << op << endl;
            cin >> ans[op];

            if (ans[pos] != ans[op]) {
                dif = pos;
            }
            if (ans[pos] == ans[op]) {
                eq = pos;
            }

            pos++;
            moves -= 2;
        }

        if (moves) { //inutil
            int aux;
            cout << 1 << endl;
            cin >> aux;
        }

    }

    for (int i = 1; i <= n; i++) {
        cout << ans[i];
    }
    cout << endl;

    char ret;
    cin >> ret;

    assert(ret == 'Y');

}



int main() {

    int t;
    cin >> t >> n;

    for (int i = 1; i <= t; i++) {
        //cout << "Case #" << i << ": ";
        solve();
    }

    return 0;
}