import strutils, sequtils, algorithm

var
  cnt = 0
  N, A = stdin.readLine.split.map parseInt

A.sort(cmp)
A.insert(0)
A.add(0)

for i in countdown(A.high - 1, 1):
  let Ai = A[i]
  if Ai != A[i - 1] and Ai != A[i + 1]: cnt += 1
  A.delete(A.high)

echo cnt