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 Go (1.6) (judge verdict: Accepted)

// Package main provides
//
// File:  c.go
// Author: ymiyamoto
//
// Created on Mon Dec 24 15:59:48 2018
//
package main

import "fmt"

func main() {
	var N int
	fmt.Scan(&N)
	ans := 0
	for i := 0; i < N; i++ {
		var a int
		fmt.Scan(&a)
		ans += a - 1
	}
	fmt.Println(ans)
}