code/online_challenges/src/codechef/RRCOPY/README.md
You had an array of integer numbers. You also had a beautiful operations called "Copy-Paste" which allowed you to copy any contiguous subsequence of your array and paste it in any position of your array. For example, if you have array [1, 2, 3, 4, 5] and copy it's subsequence from the second to the fourth element and paste it after the third one, then you will get [1, 2, 3, 2, 3, 4, 4, 5] array. You remember that you have done a finite(probably zero) number of such operations over your initial array and got an array A as a result. Unfortunately you don't remember the initial array itself, so you would like to know what could it be. You are interested by the smallest such array. So the task is to find the minimal size(length) of the array that A can be obtained from by using "Copy-Paste" operations.