// uses the recursive function write_vertical.
// Walter Savitch
// 12/4/2001

#include <iostream>

using std::cout; using std::endl; using std::cin;

void write_vertical(int n); // writes digits of n one per line

int main() {
  cout << "Enter number: ";
  int num;
  cin >> num;
  write_vertical(num);
}

// n is written to the screen vertically
// with each digit on a separate line.
void write_vertical(int n) {

    if (n < 10) {
        cout << n << endl; 
   } else{ //n is two or more digits long
        write_vertical(n/10);
        cout << (n%10) << endl;
   }
}