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 JavaScript (node.js v5.12) (judge verdict: Time Limit Exceeded)

function main(input) {
    var arr = []
    var input = input.split("\n")
    input = input[1].split(" ")
    var result = 1
    input.forEach(function(element) {
        var v = parseInt(element,10)
        result *= v
        arr.push(v)
    })
    var max = 0
    for (var i = 1; i <= result ; i++) {
        var current = 0
        for (var v in arr) {
            current += i % arr[v]
        }
      	if(current === 0) {
          break
        }
      
        if (max < current) {
            max = current
        }
    }
  	console.log(max)
  }
  main(require('fs').readFileSync('/dev/stdin', 'utf8'));