An array is monotonic if it is either monotone increasing or monotone decreasing. An array A is monotone increasing if for all i <= j, A[i] <= A[j]. An array A is monotone decreasing if for all i <= j, A[i] >= A[j]. Return true if and only if the given array A is monotonic. Example 1: Input: [1,2,2,3] Output: true Example 2: Input: [6,5,4,4] Output: true Example 3: Input: [1,3,2] Output: false Example 4: Input: [1,2,4,5] Output: true Example 5: Input: [1,1,1] Output: true Note: 1 <= A.length <= 50000 -100000 <= A[i] <= 100000