public static void Main()
int[] arr1 = { 128, 456, 789 };
int result1 = FindFirst(arr1);
int[] arr2 = { 111, 222, 333, 414, 505 };
int result2 = FindFirst(arr2);
Console.WriteLine(result1);
Console.WriteLine(result2);
public static int FindFirst(int[] arr)
for (int i = 0; i < arr.Length; i++)