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 PHP7 (7.0.15) (judge verdict: Runtime Error)

<?php
$n = trim(fgets(STDIN));
$a = trim(fgets(STDIN));
$as = explode(' ', $a);

$x = 1;
for($i=0;$i<$n;$i++) {
    $x = lcm($x, (int)$as[$i]);
}

$total=0;
foreach($as as $ax) {
    $total += $ax % $x-1;
}

echo $total;

function gcd($a, $b) {
    if ($b === 0)
        return $a;

    return gcd($b, $a % $b);
}

function lcm($a, $b) {
    return $a * $b / gcd($a, $b);
}