Recursion- Sum Of Array

Given an array of length N, you need to find and return the sum of all elements of the array.
Do this recursively.
Input Format :
Line 1 : An Integer N i.e. size of array
Line 2 : N integers which are elements of the array, separated by spaces
Output Format :
Sum
Constraints :
1 <= N <= 10^3
Sample Input 1 :
3
9 8 9
Sample Output 1 :
26
Sample Input 2 :
3
4 2 1
Sample Output 2 :
7    


****************************Code*******************************

public class Solution {

	public static int sum(int input[]) {
  
		return sum(input,0);
	}
	 private static int sum(int input[],int startIndex){
        if(startIndex==input.length)
            return 0;
        int ans=input[startIndex]+sum(input,startIndex+1);
        return ans;
	 }
}