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 C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
#define tam 300002

using namespace std;

typedef long long ll;
typedef vector <int> vi;
typedef vector <ll> vl;
typedef pair <ll, ll> dl;
typedef pair <int, int> ii;
typedef vector <ii> vii;
typedef vector <vi> graph;

bool comp(string a, string b) {
	return a.size() < b.size();
}

int main() {
	ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);

	int n;
	cin >> n;
	ll arr[n];
	ll prod = 1;
	for (int i = 0; i < n; ++i)
	{
		cin >> arr[i];
		prod *= arr[i];
	}
	ll suma = 0;
	prod--;
	for (int i = 0; i < n; ++i)
	{
		suma += (prod % arr[i]);
	}
	cout << suma << endl;
	return 0;
}