#include<iostream>
#include<cctype>
using namespace std ;
int main(){
    string name ;
    getline(cin,name);
    int m ;
    
    if(name.length()>=1&&name.length()<=100){    
        for(int i =0;i<name.length();i++){
            if(isdigit(name[i])){
                cout<<name[i];
                m+=1;
            }
            
            
        }
    }
    
    }
    if(m==0){
            cout<<"-1";
        }
       
    
}