HackerRank C- A Very Big Sum

Complete the aVeryBigSum function in the editor below. It must return the sum of all array elements.

aVeryBigSum has the following parameter(s):

ar: an array of integers .

#include<stdio.h>
int main()
{
    int n,i;
    long long int sum=0;
    scanf("%d",&n);
    long long int a[n];
    for(i=0;i<n;i++)
    {
        scanf("%lld",&a[i]);
        sum=sum+a[i];
     } 
     printf("%lld",sum);
}