C - Modulo Summation

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 $f$.

3
3 4 6

10

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

5
7 46 11 20 11

90

7
994 518 941 851 647 2 581

4527