#include<iostream>
#include<string>
using namespace std;
int main()
{
    string s,r="";
    if(!getline(cin,s))
    return 0;
    for(char c:s)
    {
    if(isdigit(c))r +=c;
    }
    if(r=="")
    {
        cout<<-1;
    }
    else
    {
    cout<<stoll(r)
    }
    return 0;
}