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 getLCM(int m, int n){
  int c,pm=m,pn=n;
  if(m<n){
    c=m;
    m=n;
    n=c;
  }
  while(n>0){
    c=n;
    n=m%n;
    m=c;
  }
  return pm*pn/m;
}

int main(void){
    int n,i,f=0,lcm=1;
    scanf("%d",&n);
    int a[n];
    for(i=0;i<n;i++){
        scanf("%d",&a[i]);
    }

    for(i=0;i<n;i++){
        lcm = getLCM(lcm,a[i]);
    }
    for(i=0;i<n;i++){
        f+=(lcm-1)%a[i];
    }
    printf("%d\n", f);
    return 0;
}