How to get difference between two array without using linq or Set oper

Question

I work on csharp
I have two arrays of string

A1 = [Watermelon, Apple, Mango, Guava, Banana]
A2 = [Orange, Kiwi, Apple, Watermelon]

i need to write code by csharp get difference between two arrays
and display difference between two arrays but without using linq or set operator

expected result

Mango

 Guava

Orange

Kiwi