Number an outline

The indent and words are right, but the numbers are all wrong.

Input

1. One
  1. One
    1. One
  1. Two
    1. One
    1. Two
      1. One
    1. Three
    1. Four
  1. Three
    1. One
      1. One
      1. Two
    1. Two
  1. Four
    1. One
    1. Two
    1. Three
    1. Four
    1. Five
    1. Six
  1. Five
    1. One
    1. Two
    1. Three
1. Two
  1. One
    1. One
    1. Two
    1. Three
    1. Four
    1. Five
  1. Two

Output

1. One
  1. One
    1. One
  2. Two
    1. One
    2. Two
      1. One
    3. Three
    4. Four
  3. Three
    1. One
      1. One
      2. Two
    2. Two
  4. Four
    1. One
    2. Two
    3. Three
    4. Four
    5. Five
    6. Six
  5. Five
    1. One
    2. Two
    3. Three
2. Two
  1. One
    1. One
    2. Two
    3. Three
    4. Four
    5. Five
  2. Two