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: Time Limit Exceeded)


#include <stdio.h>
#include <limits.h>

int main(void){
	int m,N,i = 0,max = 0,f;
	int a[100000] = {'0'};
	
	scanf("%d",&N);
	while(i < N){
		scanf("%d",&a[i]);
		++i;
	}
	for(m = 1;m < INT_MAX; ++m){
		f = 0;
		for(i = 0;i < N; ++i){
			f += (m % a[i]);
		}
		if(max < f)	max = f;
	}
	printf("%d\n",max);
	return 0;
}