2. Remove Invalid

// TARIKAT EDITION :)

#include <iostream>
#include <string>

using namespace std;

int main()
{
    string line;
    getline(cin, line);

    while (line != "end") {
        if (isdigit(line[0])) {
            cout << line << endl;
        }
        getline(cin, line);
    }

    return 0;
}