#include <iostream>
#include <algorithm>

using namespace std;

template<typename T>
inline int Max(T arr[]) {
	return distance(arr, max_element(arr, arr + 3));
}

template<typename T>
inline int Min(T arr[]) {
	return distance(arr, min_element(arr, arr + 3));
}

inline int ctoi(const char& c) {
	return c - '0';
}

int main() {
	char c[3];
	int q;

	cin >> c[0] >> c[1] >> c[2];

	for (int i = 0; i < sizeof(c);i++) {
		if (c[i] != '?') {
			c[i] = ctoi(c[i]);
		}
		else {
			q = i;
		}
	}

	string ans;
	c[q] = 1;
	if (Max(c) == 1 || Min(c) == 1) {
		ans.append("1");
	}
	c[q] = 4;
	if (Max(c) == 1 || Min(c) == 1) {
		ans.append("4");
	}
	cout << ans << endl;

	return 0;
}