using System;

using System.Linq;

public class Program {

  static int[] SubtractArrays(int[] a, int[] b) {

    Array.Reverse(a);

    Array.Reverse(b);

​

    int[] result = new int[Math.Max(a.Length, b.Length)];

    int carry = 0;

​

    for (int i = 0; i < Math.Max(a.Length, b.Length); ++i) {

      int value = (i < a.Length ? a[i] : 0) - (i < b.Length ? b[i] : 0) - carry;

​

      if (value < 0) {

        value += 10;

        carry = 1;

      }  

      else

        carry = 0;

​

      result[i] = value;

    }

​

    int size = result.Length;

​

    for (int i = result.Length - 1; i >= 1; --i)

      if (result[i] != 0)

        break;

      else

        size -= 1;

​

    Array.Resize(ref result, size);

​

    // Let's restore a and b

    Array.Reverse(a);

    Array.Reverse(b);

    Array.Reverse(result);

​

    return result;

  }

  public static void Main() {

    int[] a = "5,475,982,475,984,574,238,975,248,522,952,789,229,899,999,999,9"

      .Where(c => c >= '0' && c <= '9')

      .Select(c => c - '0')

      .ToArray();

​

    int[] b = "5,475,982,475,984,574,238,975,248,522,952,789,229,899,999,999,8"

     .Where(c => c >= '0' && c <= '9')

     .Select(c => c - '0')

     .ToArray();

​

    int[] c = SubtractArrays(a, b);

​

    Console.Write(string.Concat(c));

  }

}