Unfortunately, a mistake was found in the proof of the author's solution to this problem. Currently, we don't know the absolutely correct solution. However, you can solve this task, but if your solution passes all the tests, it is not guaranteed to be correct. If your solution has passed all the tests, and you are sure that it is correct, you can write to one of the contest authors about it. Sometimes Mister B has free evenings when he doesn't know what to do. Fortunately, Mister B found a new game, where the player can play against aliens. All characters in this game are lowercase English letters. There are two players: Mister B and his competitor. Initially the players have a string s consisting of the first a English letters in alphabetical order (for example, if a = 5 , then s equals to " abcde "). The players take turns appending letters to string s . Mister B moves first. Mister B must append exactly b letters on each his move. He can arbitrary choose these letters. His opponent adds exactly a letters on each move. Mister B quickly understood that his opponent was just a computer that used a simple algorithm. The computer on each turn considers the suffix of string s of length a and generates a string t of length a such that all letters in the string t are distinct and don't appear in the considered suffix. From multiple variants of t lexicographically minimal is chosen (if a = 4 and the suffix is " bfdd ", the computer chooses string t equal to " aceg "). After that the chosen string t is appended to the end of s . Mister B soon found the game boring and came up with the following question: what can be the minimum possible number of different letters in string s on the segment between positions l and r , inclusive. Letters of string s are numerated starting from 1 . First and only line contains four space-separated integers: a , b , l and r ( 1 ≤ a , b ≤ 12 , 1 ≤ l ≤ r ≤ 10 9 ) — the numbers of letters each player appends and the bounds of the segme