#include <iosream>
using namespace std;
int main(){
    string s;
    cin>>s;
    string result=="";
    if(s.length()>=1&& s.length()<100){
        for (int i=0 ;s.length();i++){
            if(isdigit(s[i])){
                result +=s[i];
            }
        }
        if(result.length()==0){
            cout<<-1;
        }
        else{
            int f=stoi(result);
            cout<<f;
        }
    }
    return 0;
}