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 <iostream> // cin, cout, cerr, clog
#include <algorithm> // min, max, sort, swap
#include <numeric> // iota, accumulate, inner_product
#include <cmath> // long, trig, pow
#include <string> // string, stoi, to_string
#include <vector> // vector
#include <queue> // queue, priority_queue
#include <deque> // deque
#include <stack> // stack
#include <map> // key-value pairs sorted by keys
#include <set> // set
#include <unordered_map> // hashed by keys
#include <unordered_set> // hashed by keys
#include <iomanip> // cout<<setprecision(n)
#include <functional> // std::function<void(int)>
using namespace std;
#define rep(i,n) rep1(i,0,n)
#define rep1(i,m,n) for(int i=m;i<(n);i++)
#define All(v) (v).begin(),(v).end()
using ll = long long;
const int inf = 1<<30;
const ll mod = 1000000007;
const ll INF = 100000000000000000LL;
const double PI = acos(-1);
int main(){
    int n;
    cin>>n;
    int res = 0;
    rep(i,n){
        int a;
        cin >> a;
        a--;
        res+=a;
    }
    cout << res << endl;
}