input: Write a python function to find the longest increasing subsequence in an array.
  assert find_longest_increasing_subsequence([10, 22, 9, 33, 21, 50, 41, 60, 80]) == 6
  assert find_longest_increasing_subsequence([3, 10, 2, 1, 20]) == 3
  assert find_longest_increasing_subsequence([3, 2]) == 1
output: def find_longest_increasing_subsequence(arr):
      if not arr:
          return 0
  
      n = len(arr)
      lis = [1] * n
  
      for i in range(1, n):
          for j in range(0, i):
              if arr[i] > arr[j] and lis[i] < lis[j] + 1:
                  lis[i] = lis[j] + 1
  
      return max(lis)