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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <algorithm>
#include <cmath>
#include <vector>
#include <functional>
#include <cstdlib>
#include <map>
#include <set>
#include <iostream>
#include <string>
#include <ctype.h>
#include <climits>
#include <queue>
using namespace std;
typedef long long ll;
#define REP(i, n) for(ll i = 0; i < (ll)(n); ++i)
template<class T> inline bool chmax(T& a, T b) { if(a < b){ a=b; return 1; } return 0;}
template<class T> inline bool chmin(T& a, T b) { if(a > b){ a=b; return 1; } return 0;}

int main(){
	ll n;
	cin >> n;
	vector<ll> a(n);
	REP(i,n) cin >> a[i];
	
	ll ans=-1*n;
	REP(i,n){
		ans += a[i];
	}
	
	cout << ans << endl;
	
	return 0;
}