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 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
 
int main(void)
{
  int N,i,j,b,c,d,e,f=0,r,k;

  int a[3000];
  scanf("%d",&N);
  for(i = 0;i<N;i++)
  	scanf("%d",&a[i]);

  d = a[0];

  for(j = 1;j<N;j++){
  	e = d;
  	r = a[j];
  	while(r!=0){
  		c = b%r;
  		b = r;
  		r = c;
  	}
  	d=a[j]/b*e;
  }
  for(k=0;k<N;k++)
  	f=f+(e-1)%a[k];
  printf("%d\n",f);
  
  return 0;
}