#include"bits/stdc++.h"
using namespace std;


int main() {
	vector<char> c(3);
	int h;
	for (int i = 0; i < 3; i++) {
		cin >> c[i];
		if (c[i] == '?')
			h = i;
	}
	c[h]='1';
	//cout << c[0] <<" "<< c[1] <<" "<< c[2] << endl;
	if ((c[1]<c[0] && c[1]<c[2]) || (c[1]>c[0] && c[1]>c[2])) {
		cout << c[h];
	}
	c[h]='4';
	//cout << c[0] << " " << c[1] << " " << c[2] << endl;
	if ((c[1]<c[0] && c[1]<c[2]) || (c[1]>c[0] && c[1]>c[2])) {
		cout << c[h];
	}
	cout << endl;
}