#include<bits/stdc++.h>

using namespace std;
using ll=long long;
#define rep2(i, a, n) for(int i = (a); i < (n); i++)
#define rep(i, n) rep2(i,0,n)
#define repe(i,a) for(auto &i:a)

int main(){
  cin.tie(nullptr);ios_base::sync_with_stdio(false);
  int n=3;
  char hoge[n];
  rep(i,n)cin>>hoge[i];
  string t="14";
  rep(i,n){
    if(hoge[i]=='?'){
      repe(c,t){
        hoge[i]=c;
        bool ok=false;
        if(
            (hoge[0]<hoge[1] and hoge[2]<hoge[1])
            ||
            (hoge[0]>hoge[1] and hoge[2]>hoge[1])
          )ok=true;
        if(ok)cout<<c;
      }
      cout<<endl;
      return 0;
    }
  }
}