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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
class Program
{
    static void Main(string[] args)
    {
            // 入力
            int iN = int.Parse(Console.ReadLine().Trim());
            string[] sInp = Console.ReadLine().Trim().Split(' ');
            List<int> lstNum = new List<int>();
            for (int i = 0; i < sInp.Length; i++)
            { lstNum.Add(int.Parse(sInp[i])); }

            // 解析
            int iOut = 0;
            for (int i = 0; i < lstNum.Count; i++)
            {
                iOut += lstNum[i] - 1;
            }

            //出力
            Console.WriteLine("{0}", iOut.ToString());

#if DEBUG
            Console.WriteLine("続行するには何かキーを押してください．．．");
            Console.ReadKey();
#endif

    }

}