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)

/*Infor {{{
 ******************************************************
 * > File Name: a.cpp
 * > Author: samcompu
 * > Mail: admin@samcompu.com
 * > Created Time: 2018/7/21 12:13:06
 ******************************************************
}}}*/

#include <bits/stdc++.h>

using namespace std;

/*Abbreviation {{{ */
#define FOR(i,a,b) for(int i = (int)(a); i <= (int)(b); i++)
#define ROF(i,a,b) for(int i = (int)(a); i >= (int)(b); i--)
#define cini(a) scanf("%d", &(a))
#define cinc(a) scanf("%c", &(a))
#define cinl(a) scanf("%lld", &(a))
#define cins(a) scanf("%s", (a))
#define cind(a) scanf("%lf", &(a))
#define coui(a) printf("%d", (a))
#define couc(a) printf("%c", (a))
#define coul(a) printf("%lld", (a))
#define cous(a) printf("%s", (a))
#define coud(a) printf("%f", (a))
#define SPA printf(" ")
#define LIN printf("\n")
#define ull unsigned long long int
/*}}}*/

/*Constant {{{*/
const int MAXN = 3000;
/*}}}*/

/*Class {{{*/
/*}}}*/

/*Variable {{{*/
int a[MAXN + 1];
/*}}}*/

/*Declare {{{*/
/*}}}*/

/*Main {{{*/
int main() {
  int n;
  cini(n);
  int ans = 0;
  FOR(i, 1, n) {
    int x;
    cini(x);
    ans += x - 1;
  }
  coui(ans), LIN;
  return 0;
}
/*}}}*/

/*Define {{{*/
/*}}}*/