output_description: Print the maximum value of f.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      a_1 a_2 ... a_N
attempt: ###############################################################################
  
  from sys import stdout
  from bisect import bisect_left as binl
  from copy import copy, deepcopy
  from collections import defaultdict
  
  
  mod = 1
  
  
  def intin():
      input_tuple = input().split()
      if len(input_tuple) <= 1:
          return int(input_tuple[0])
      return tuple(map(int, input_tuple))
  
  
  def intina():
      return [int(i) for i in input().split()]
  
  
  def intinl(count):
      return [intin() for _ in range(count)]
  
  
  def modadd(x, y):
      global mod
      return (x + y) % mod
  
  
  def modmlt(x, y):
      global mod
      return (x * y) % mod
  
  
  def lcm(x, y):
      while y != 0:
          z = x % y
          x = y
          y = z
      return x
  
  
  def combination(x, y):
      assert x >= y
  
      if y > x // 2:
          y = x - y
  
      ret = 1
  
      for i in range(0, y):
          j = x - i
          i = i + 1
  
          ret = ret * j
          ret = ret // i
  
      return ret
  
  
  def get_divisors(x):
      retlist = []
      for i in range(1, int(x**0.5) + 3):
          if x % i == 0:
              retlist.append(i)
              retlist.append(x // i)
      return retlist
  
  
  def get_factors(x):
      retlist = []
      for i in range(2, int(x**0.5) + 3):
          while x % i == 0:
              retlist.append(i)
              x = x // i
      retlist.append(x)
      return retlist
  
  
  def make_linklist(xylist):
      linklist = {}
      for a, b in xylist:
          linklist.setdefault(a, [])
          linklist.setdefault(b, [])
          linklist[a].append(b)
          linklist[b].append(a)
      return linklist
  
  
  def calc_longest_distance(linklist, v=1):
      distance_list = {}
      distance_count = 0
      distance = 0
      vlist_previous = []
      vlist = [v]
      nodecount = len(linklist)
  
      while distance_count < nodecount:
          vlist_next = []
          for v in vlist:
              distance_list[v] = distance
              distance_count += 1
              vlist_next.extend(linklist[v])
          distance += 1
          vlist_to_del = vlist_previous
          vlist_previous = vlist
          vlist = list(set(vlist_next) - set(vlist_to_del))
  
      max_distance = -1
      max_v = None
      for v, distance in distance_list.items():
          if distance > max_distance:
              max_distance = distance
              max_v = v
  
      return (max_distance, max_v)
  
  
  def calc_tree_diameter(linklist, v=1):
      _, u = calc_longest_distance(linklist, v)
      distance, _ = calc_longest_distance(linklist, u)
      return distance
  
  
  ###############################################################################
  
  
  def main():
      n = intin()
      alist = intina()
  
      ans = 0
      for a in alist:
          ans += a - 1
      print(ans)
  
  
  if __name__ == "__main__":
      main()
  
problem_description: Statement
  
  You are given N positive integers a_1, a_2, ..., a_N.
  
  For a non-negative integer m, let f(m) = (m\ mod\ a_1) + (m\ mod\ a_2) + ... +
  (m\ mod\ a_N).
  
  Here, X\ mod\ Y denotes the remainder of the division of X by Y.
  
  Find the maximum value of f.
samples: [{"input": "3\n    3 4 6", "output": "10\n    \n\nf(11) = (11\\ mod\\ 3) + (11\\ mod\\ 4) + (11\\ mod\\ 6) = 10 is the maximum value\nof f.\n\n* * *"}, {"input": "5\n    7 46 11 20 11", "output": "90\n    \n\n* * *"}, {"input": "7\n    994 518 941 851 647 2 581", "output": "4527"}]