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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        String N = scanner.nextLine();
        String a_list = scanner.nextLine();
        List<Integer> a = Arrays.asList(a_list.split(" ")).stream().map(s -> Integer.parseInt(s)).collect(Collectors.toList());

        scanner.close();

        int max_m = 1;
        for (int ai : a) {
            max_m = max_m * ai;
        }

        int max = 0;
        for (int i = 0; i < max_m; ++i) {
            int res = 0;
            // System.out.println("---");
            // System.out.println(i);
            for (int j = 0; j < a.size(); ++j) {
                res += i % a.get(j);
                // System.out.println(a.get(j) + " : "  + (i % a.get(j)));
                // System.out.println(res);
            }

            if (res > max) {
                max = res;
            }
        }

        System.out.print(max);
    }
}