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

    //公倍数を求める
    int M = 1;
    int len = sizeof(a)/sizeof(a[0]);
    for(int i = 0;i < len;i++){
        if(M % a[i] != 0)M *= a[i];
    }
    int max = 0;
    for(int m = M;m < 2 * M;m++){
        int f = 0;
        for(int i = 0;i < N;i++){
            f += m % a[i];
        }
        if(f > max)max = f;
    }
    printf("%d\n",max);
    return 0;
}