Outside the bounds of the array

using System;
using System.Linq;

class LargestCommonEnd
{
    static void Main(string[] args)
    {
        string[] arr = Console.ReadLine().Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
        string[] arr2 = Console.ReadLine().Split(new char[] {' '}, StringSplitOptions.RemoveEmptyEntries);
        int Similar = Math.Min(arr.Length, arr2.Length);
        for (int i = 0; i <= Similar; i++)
        {
            if (arr[i]==arr2[i])
            {
                Console.WriteLine(arr.Length);
            }
        }
    }
}