redskins

I was wondering if anyone could write code for this program. Its the usual Necklace Problem I'll give you the problem.A Necklace is a collection of numbers that begins with two single digit integers, the next number is obtained by adding the first two digits together and saving only the ones digit. This process is repeated until the 'necklace' closes by returning to the original two numbers. I think it is a Do While Loop but i am not sure. Thankyou