input: Write a function to find the maximum sum of an array of non-negative integers, given an upper limit value. If the array is empty, return 0.
  assert findMaxSum(10, [1, 3, 5, 4, 2, 6])==9
  assert findMaxSum(7, [1, 3, 5, 4, 2, 6])==7
  assert findMaxSum(3, [1, 3, 5, 4, 2, 6])==3
  assert findMaxSum(15, [1, 3, 5, 4, 2, 6])==15
  assert findMaxSum(5, [1, 3, 5, 4, 2, 6])==5
  assert findMaxSum(0, [1, 3, 5, 4, 2, 6])==0
  assert findMaxSum(10, [])==0
output: def findMaxSum(limit, arr):
      if not arr:
          return 0
      arr.sort(reverse=True)
      current_sum = 0
      for num in arr:
          if current_sum + num <= limit:
              current_sum += num
          if current_sum == limit:
              break
      return current_sum