public static void Main()
Console.WriteLine("Hello World");
static int CountDivisible(int a, int b, int c)
int first = (a % c == 0) ? a : a + (c - a % c);
int last = (b % c == 0) ? b : b - (b % c);
return (last - first) / c + 1;
string[] input = Console.ReadLine().Split();
int a = int.Parse(input[0]);
int b = int.Parse(input[1]);
int c = int.Parse(input[2]);
Console.WriteLine(CountDivisible(a, b, c));