#include <iostream>
#include <fstream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <cstring>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <algorithm>
using namespace std;

#define REP(i,n) for(int i=0; i<n; ++i)
#define FOR(i,a,b) for(int i=a; i<=b; ++i)
#define FORR(i,a,b) for (int i=a; i>=b; --i)
#define ALL(c) (c).begin(), (c).end()

typedef long long ll;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef vector<VL> VVL;
typedef vector<VI> VVI;
typedef pair<int,int> P;
typedef pair<ll,ll> PL;

bool check(int x[3]){
    int a = x[0], b = x[1], c = x[2];
    return (a != c) && ((b > a && b > c) || (b < a && b < c));
}

int main() {
    int a[3], x;
    REP(i,3){
        char c;
        cin >> c;
        if (c == '?') x = i;
        else a[i] = c - '0';
    }

    a[x] = 1;
    if (check(a)) cout << '1';
    a[x] = 4;
    if (check(a)) cout << '4';
    cout << endl;

    return 0;
}