Java Loops and Introduction to Arrays - Post Class - Mohit and array

Q18-Mohit has an array of N integers containing all elements from 1 to N, somehow he lost one element from the array.
Given N-1 elements your task is to find the missing one.
Ans-import java.io.*; // for handling input/output
import java.util.*; // contains Collections framework

// don't change the name of this class
// you can add inner classes if needed
class Main {
    public static void main (String[] args){
                      // Your code here
        Scanner s=new Scanner(System.in);
            int N=s.nextInt();
            int arr[]=new int[N];
            for(int i=0;i<N-1;i++){
                arr[i]=s.nextInt();
            }
            Arrays.sort(arr);
            int sumOfAll = (N*(N+1))/2;
      int sumOfArray = 0;
      for(int j=0; j<=N-1; j++) {
         sumOfArray = sumOfArray+arr[j];
      }
      int missingNumber = sumOfAll-sumOfArray;
      System.out.println(missingNumber);
   }
}