function findDeepestLevel(arr, currentLevel = 1) {
  // Base case: when the array is empty, return the current level
  if (arr.length === 0) {
    return currentLevel;
  }

  let maxLevel = currentLevel;

  for (let i = 0; i < arr.length; i++) {
    if (Array.isArray(arr[i])) {
      // Recursive case: if the element is an array, call the function recursively
      const depth = findDeepestLevel(arr[i], currentLevel + 1);
      if (depth > maxLevel) {
        maxLevel = depth;
      }
    }
  }

  return maxLevel;
}

// Test cases
console.log(findDeepestLevel([1, [2, [3, [4]], 5]])); // => 4
console.log(findDeepestLevel([1, 2, 3, 4, 5])); // => 1
console.log(findDeepestLevel([])); // => 1
console.log(findDeepestLevel([1, [2], [3, [4, [5]]]])); // => 4
console.log(findDeepestLevel([1, [2, [3]], [4, [5, [6]]]])); // => 4
