import sequtils, strutils let n = parseInt readLine stdin xys = n.newSeqWith stdin.readLine.split.map parseFloat var ans = 2 cnt: int for i in 0 ..< n.pred 2: for j in i.succ ..< n.pred: var x1, x2, x3, y1, y2, y3: float (x1, y1) = xys[i] (x2, y2) = xys[j] let dx = x2 - x1 dy = y2 - y1 cnt = 2 for k in j.succ ..< n: (x3, y3) = xys[k] if dx == 0 and x1 == x3: inc cnt elif dy == 0 and y1 == y3: inc cnt elif dy / dx * (x3 - x1) == y3 - y1: inc cnt ans = ans.max cnt echo ans