#include<bits/stdc++.h>
using namespace std;
int main(){
    vector<int> a(3),b={1,4};
    for(int i=0;i<3;++i){
        char c;
        cin>>c;
        a[i]=c-'0';
    }
    int ind=find(a.begin(),a.end(),15)-a.begin();
    string ans;
    for(int i=0;i<2;++i){
        a[ind]=b[i];
        auto mn=minmax_element(a.begin(),a.end());
        if(a[1]==*mn.first||a[1]==*mn.second)ans+=to_string(b[i]);
    }
    cout<<ans<<endl;
}