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: Accepted)

    #include<stdio.h>
    #include<stdlib.h>
    int main(){
      int n,sum;
      int *a;
      scanf("%d",&n);
     
      a = (int *)calloc(n,sizeof(int));
      if(a == NULL) exit(-1);
     
      sum = 0;
      for(int i = 0;i < n; i++){
        scanf("%d",&a[i]);
        a[i]--;
        sum += a[i];
      }
      free(a);
      printf("%d",sum);
      return 0;
    }