Untitled

#include <iostream>

using namespace std;
int main()
{
    setlocale(LC_ALL, "Russian");
    string a,b[] = {"1","2","3","4","5","6","7","8","9","0" };
    cin >> a;
    for (int i = 0; i < 10; i++)
    {
        if (b[i] == a) {
            cout << "YES";
            return 0;
        }
    }
    cout << "NO";
}