Problem:
Score : 300 points

Problem 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.

Constraints

All values in input are integers.

2 \leq N \leq 3000

2 \leq a_i \leq 10^5

Input

Input is given from Standard Input in the following format:

N
a_1 a_2 ... a_N

Output

Print the maximum value of f.

Sample Input 1

3
3 4 6

Sample Output 1

10

f(11) = (11\ mod\ 3) + (11\ mod\ 4) + (11\ mod\ 6) = 10 is the maximum value of f.

Sample Input 2

5
7 46 11 20 11

Sample Output 2

90

Sample Input 3

7
994 518 941 851 647 2 581

Sample Output 3

4527

Solution in Pascal (FPC 2.6.2) (judge verdict: Accepted)

uses
  SysUtils,
  Classes;

var
	a, i, total : Integer;
	atype : array of Integer;
	str : String;
	strlist : TStringList;
begin
	readln(a);
	setLength(atype, a);
	
	readln(str);
	strlist := TStringList.Create;
	try
		strlist.Delimiter := ' ';
		strlist.DelimitedText := str;
		for i := 0 to a - 1 do
			atype[i] := StrToInt(strlist.Strings[i]);
	finally
		strlist.free;
		end;
	total := 0;	
	for i := 0 to a - 1 do
		begin
		total := total + (atype[i] - 1);
		end;
		writeLn(total);
end.