#include<iostream>
#include<string>
using namespace std;
int main(){
    string s;
    cin>>s;
    string result="";
    for(int i=0;i<s.length();i++){
        if(isdigit(s[i])){
            result+=s[i];
        }
    }
    if(result.length()==0){
        cout<<i;
    }else{
        cout<<result;
    }
    result 0;
}