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() {
  long long int n, a[3001], i, j, f, max, fmax=0;;
  scanf("%lld", &n);
  max=0;
  for(i=0; i<n; ++i) {
    scanf("%lld", a+i);
    if(a[i]>max) max=a[i];
  }
  for(i=max; i<(max*2); ++i)
  {
    f=0;
    for(j=0; j<n; ++j) {
      f+=i%a[j];
    }
    if(f>fmax) fmax=f;
  }
  printf("%lld", fmax);
  return 0;
}