// editor4
#include <iostream>
#include <string>
using namespace std;

int main(){
    string s;
    getline(cin, s);
    
    if(s.length()==0){
        cout<<"Invalid input";
        return 0;
    }
    
    string result = "";
    
    for(int i = 0; i<s.length();i++){
        if(s[i]<='0' && s[i]<='9'){
            cout<<"Invalid input";
            return 0;
        }
        
        if(s[i]!=''){
            result+=s[i];
        }
    }
    cout<<result;
    return 0;
}