Runtime Error (NZEC) in simple code

Question

I'm getting runtime error (NZEC) when running the following code over at SPOJ. I'd be very thankful if any of you would kindly point out what's going on.

//0<=A<=B<=10^18, 1<=N<=10^18
using System;
class any
{
static void Main()
 {
    long t = long.Parse(Console.ReadLine());
    ulong a, b, n;

    for(long k = 0; k < t; k++)
     {
        string[]s = Console.ReadLine().Split(' ');
        a = ulong.Parse(s[0]);
        b = ulong.Parse(s[1]);
        n = ulong.Parse(s[2]);
        Console.WriteLine(diviEntre2(a, b, n));
     }
 }
static ulong diviEntre2(ulong f, ulong c, ulong n)
{
   ulong k, s, m;

    if (f == c && c % n == 0 && f != 0) k = c/n;

    else
     {
      s = f/n;
      m = c/n;

      k = m - s;
     }

  return k;
}
}

Answer 1

NZEC stands for Non Zero Exit Code. For C users, this will be generated if your main method does not have a return 0; statement. Other languages like Java/C++ could generate this error if they throw an exception.