#include <bits/stdc++.h>
#define endl "\t--- in " << __LINE__ << endl
using namespace std;
int nn[1000010], mm[1000010];
string ss[1000010];
vector<int> calc(int n, int m, string s, int ed) {
	int cnt = 0;
	for (int i = 0; i <= ed; i++)
		cnt += s[i] == '0';
	vector<int> a, b;
	int sum = m - cnt - (s[ed] == '1');
	for (int i = 0; i < ed; i++) {
		if (s[i] == '0' || sum) b.push_back(s[i] - '0'), sum -= s[i] - '0';
		else a.push_back(s[i] - '0');
	}
	b.push_back(s[ed] - '0');
	for (int i = ed + 1; i < s.size(); i++)
		a.push_back(s[i] - '0');
	vector<int> c(max(a.size(), b.size()) + 1);
	reverse(a.begin(), a.end()), reverse(b.begin(), b.end());
	a.resize(c.size()), b.resize(c.size());
	int lst = 0;
	for (int i = 0; i < c.size(); i++)
		c[i] = (a[i] + b[i] + lst) & 1, lst = (a[i] + b[i] + lst) >> 1;
	while (c.size() > 1 && c.back() == 0) c.pop_back();
	reverse(c.begin(), c.end());
	return c;
}
void Solve(int n, int m, string s) {
	if (n < m) swap(n, m);
	vector<int> res;
	int cnt = 0;
	for (int i = 0; i < m; i++)
		cnt += s[i] == '0';
	for (int ed = m - 1; ed < s.size() && cnt + s[ed] - '0' <= m; cnt += (s[++ed] == '0')) {
		vector<int> c = calc(n, m, s, ed);
		if (c.size() > res.size() || (c.size() == res.size() && c > res))
			res = c;
	}
	for (int x : res)
		cout << x;
	cout << "\n";
}
void Solve2(int n, int m, string s) {
	if (n < m) swap(n, m);
	int l = 0, r = 0;
	for (int i = 0; i < m; i++)
		l += s[i] == '0';
	for (int i = 0; i < s.size(); i++)
		r += s[i] == '0';
	r = min(r, m);
	while (l + 30 < r) {
		int lmid = (l * 2 + r) / 3, rmid = (l + r * 2) / 3;
		int now = 0;
		for (int i = 0; i < s.size(); i++) {
			now += s[i] == '0';
			if (now == lmid) {lmid = i; break;}
		}
		now = 0;
		for (int i = 0; i < s.size(); i++) {
			now += s[i] == '0';
			if (now == rmid) {rmid = i; break;}
		}
		auto cl = calc(n, m, s, max(m - 1, lmid)), cr = calc(n, m, s, max(m - 1, rmid));
		if (cl.size() > cr.size() || (cl.size() == cr.size() && cl > cr))
			r = rmid;
		else l = lmid;
	}
	vector<int> res;
	for (int i = l; i <= r; i++) {
		int now = 0, x;
		for (int j = 0; j < s.size(); j++) {
			now += s[j] == '0';
			if (now == i) {x = j; break;}
		}
		auto c = calc(n, m, s, max(m - 1, x));
		if (c.size() > res.size() || (c.size() == res.size() && c > res))
			res = c;
	}
	for (int x : res)
		cout << x;
	cout << "\n";
}
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0), cout.tie(0);
	int T, sum = 0;
	cin >> T;
	for (int i = 1; i <= T; i++) {
		cin >> nn[i] >> mm[i] >> ss[i];
		sum += nn[i] + mm[i];
	}
	if (sum <= 20000) {
		for (int i = 1; i <= T; i++)
			Solve(nn[i], mm[i], ss[i]);
	}
	else {
		for (int i = 1; i <= T; i++)
			Solve2(nn[i], mm[i], ss[i]);
	}
	return 0;
}