HaveEqualLines

using System;
using System.IO;

class HaveEqualLines
{
    static void Main()
    {
        int n = 0;

        using (StreamReader input1 = new StreamReader("Miha1.txt"))
        using (StreamReader input2 = new StreamReader("Miha2.txt"))
            for (string line1, line2; (line1 = input1.ReadLine()) != null && (line2 = input2.ReadLine()) != null; n++)
                if (line1 == line2) Console.WriteLine("Line {0} is equal", n);
                else Console.WriteLine("Line number {0} is different", n);
    }
}