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.*;
import static java.lang.Math.*;
import java.math.BigInteger;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		
		// 入力
		int n = sc.nextInt();
		long[] a = new long[n];
		for(int i = 0; i < n; i++){
		    a[i] = sc.nextLong();
		}
		
		// 計算
		long result = 0;
		long lcm = 1;
		for(int i = 0; i < n; i++){
		    long gcd = gcd(lcm, a[i]);
		    lcm = lcm*a[i]/gcd;
		}
		for(int i = 0; i < n; i++){
		    result += (lcm - 1)%a[i];
		}
		
		// 出力
		System.out.println(result);
	}
	
	static long gcd(long x, long y){
	    if(y == 0) return x;
	    return gcd(y , x%y);
	}
}