#include <iostream>
#include <string>
#include <algorithm>
#include <cmath>
using namespace std;
int main() {
	long long n, v[200000];
	long long ans = 0, ans1 = 0, ans2 = 0;
	cin >> n;
	ans = n * (n + 1) / 2;
	for (int i = 0; i < n; i++) {
		cin >> v[i];
		ans1 += v[i];
	}
	ans2 = ans1 - ans;
	cout << ans2 << endl;
	return 0;
}

### Prompt

Please create a solution in cpp to the following problem:

Gag

Segtree has $ N $ of "gags", each with a value of $ V_i $.

Segtree decided to publish all the gags in any order.

Here, the "joy" you get when you publish the $ i $ th gag to the $ j $ th is expressed as $ V_i --j $.

Find the maximum sum of the "joy" you can get.

input

Input is given from standard input in the following format.


$ N $
$ V_1 $ $ V_2 $ $ \ ldots $ $ V_N $


output

Please output the maximum value of the sum of "joy". However, the value does not always fit in a 32-bit integer.

Insert a line break at the end.

Constraint

* $ 1 \ leq N \ leq 10 ^ 5 $
* $ 1 \ leq V_i \ leq 10 ^ 5 $
* All inputs are integers.



Input example 1


1
59549


Output example 1


59548


Input example 2


Five
2 1 8 5 7


Output example 2


8






Example

Input

1
59549


Output

59548

### Response

```cpp
#include <iostream>
#include <string>
#include <algorithm>
#include <cmath>
using namespace std;
int main() {
	long long n, v[200000];
	long long ans = 0, ans1 = 0, ans2 = 0;
	cin >> n;
	ans = n * (n + 1) / 2;
	for (int i = 0; i < n; i++) {
		cin >> v[i];
		ans1 += v[i];
	}
	ans2 = ans1 - ans;
	cout << ans2 << endl;
	return 0;
}

```