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

int main()
{
	char c[3];
	cin >> c[0] >> c[1] >> c[2];

	int idx;
	vector<int> n( 3 );
	for( int i = 0; i < 3; i++ ) {
		if( c[i] == '?' ) idx = i;
		else n[i] = c[i] - '0';
	}

	n[idx] = 1;
	if( n[0] < n[1] && n[2] < n[1] || n[0] > n[1] && n[2] > n[1] ) cout << 1;
	n[idx] = 4;
	if( n[0] < n[1] && n[2] < n[1] || n[0] > n[1] && n[2] > n[1] ) cout << 4;
	cout << endl;
}