If staments with or

Hello im trying to test for files and if would like it to test for all of them and when one does not exist then it will do code. I tried the || but it doesnt seem to work so i was wondering if its the right one that i need to be using..

Example:

    if (File.Exists("//1.txt") || File.Exists("//2.txt") || File.Exists("//2.txt") )
    {
        //DO NOTHING
    }
    else
    {
    File.Create("//1.txt");
    File.Create("//2.txt");
    File.Create("//3.txt"); 
    }