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 (Clang 3.8.0) (judge verdict: Accepted)

#include <iostream>
#include <string>
#include <array>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <algorithm>
#include <cmath>
#include <iomanip>

#define FOR(i, a, b) for(decltype(b) i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;

using namespace std;

#ifdef INPUT
#include <sstream>
stringstream input(R"(
5
7 46 11 20 11
)");
#define cin input
#endif

int main()
{
	int n;
	cin >> n;

	int r = 0;
	REP (i, n)
	{
		int a;
		cin >> a;
		r += a - 1;
	}

	cout << r << endl;

	return 0;
}