Array sorting problem

Question

I have 3 array of int data type and i want to find common numbers from arrays without using standard method.

 

I tried this:--

 

class Program

{

static void Main(string[] args)

{

int[] array1 = { 1, 4, 2, 8, 7 };

int[] array2 = { 7, 5, 9, 1, 0,2,15};

int[] array3 = { 7, 5, 9, 1, 0, 2, 15,56,23 };

for (int i=0; i<array1.Length;i++)

{

for (int j = 0; j < array2.Length; j++)

{

for (int k = 0; k < array1.Length; k++)

{

if (array1[i] == array2[j] || array1[j] == array2[k])

{

Console.WriteLine(array1[i]);

}

}

}

}

Console.ReadKey();

}

}