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: Accepted)

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
using vi = vector<int>;
using vll = vector<ll>;
using P = pair<int, int>;

const int INF = 1e9;
const ll INFLL = 1e18;
const int MOD = 1e9 + 7;
const int NIL = -1;
const ld PI = acosl(-1);

#define rep(i,n) for(int i=0; i<(n); ++i)
#define all(n) n.begin(),n.end()

int main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);
	//cout << fixed << setprecision(6);
	int n; cin >> n;
	vi a(n);
	rep(i, n) cin >> a[i];

	ll ans = 0;
	rep(i, n) ans += a[i];
	ans -= n;

	cout << ans << endl;
	return 0;
}