#include <iostream>
#include <fstream>
#include <cstdio>
#include <sstream>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <string>
#include <map>
#include <vector>
#include <set>
#include <queue>
#include <deque>
#include <ctime>
#include <cstdlib>

using namespace std;

#define sz(x) ((int)((x).size()))

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;

const double EPS = 1e-9;

int n, m, q;
ll cur[1050];
char a[50], b[1050];
ll state;

void solve() {
	for (int i = 0; i < m; i++) {
		cur[i] = (1LL << n) - 1;
	}
	state = 0;
	while (q-- > 0) {
		scanf("%s%s", a, b);
		for (int i = 0; i < n; i++) {
			if (a[i] == '1') {
				state ^= (1LL << i);
			}
		}
		if (state != 0) {
			for (int i = 0; i < m; i++) {
				if (b[i] == '1') {
					cur[i] &= state;
				} else {
					cur[i] &= (((1LL << n) - 1) ^ state);
				}
			}
		}
	}
	for (int i = 0; i < m; i++) {
		int id = -1;
		for (int j = 0; j < n; j++) {
			if ((cur[i] & (1LL << j)) != 0) {
				if (id == -1) {
					id = j;
				} else {
					id = -2;
				}
			}
		}
		if (id < 0)
			putchar('?');
		else
			putchar((id < 10 ? '0' + id : 'A' + id - 10));
	}
	puts("");
}

int main() {
	//freopen(".in", "r", stdin);
	//freopen(".out", "w", stdout);

	while (scanf("%d%d%d", &n, &m, &q) == 3 && n != 0) {
		solve();
	}

	return 0;
}
