Given three integer arrays arr1, arr2 and arr3 sorted in strictly increasing order, return a sorted array of only the integers that appeared in all three arrays. Example 1: Input: arr1 = [1,2,3,4,5], arr2 = [1,2,5,7,9], arr3 = [1,3,4,5,8] Output: [1,5] Explanation: Only 1 and 5 appeared in the three arrays. Example 2: Input: arr1 = [197,418,523,876,1356], arr2 = [501,880,1593,1710,1870], arr3 = [521,682,1337,1395,1764] Output: [] Constraints: 1 <= arr1.length, arr2.length, arr3.length <= 1000 1 <= arr1[i], arr2[i], arr3[i] <= 2000