You will be given a map of the bunker. The map will consist of bombs ('*'), empty cells ('.') and secret objects ('?') arranged on a regular grid. For security reasons, in case of danger, all secret objects in the bunker should be destroyed by the explosion of any one bomb. A bomb explosion destroys all objects in range D, where D depends on the bomb type. A bomb explosion also causes all other bombs in range D to explode. More formally, an item (a secret object or a bomb) will be affected by a bomb explosion if the distance between the centers of their cells is not greater than D.
You will be given a String field. Return the minimal value of D that will ensure that all secret objects will be destroyed by the explosion of any one bomb.
|-||The returned value must be accurate to 1e-9 relative or absolute.|
|-||field will contain between 1 and 50 elements, inclusive.|
|-||Each element of field will contain between 1 and 50 characters, inclusive.|
|-||Each element of field will contain the same number of characters.|
|-||field will contain only the characters '*', '.', and '?'.|
|-||field will contain between 1 and 100 '*' characters, inclusive.|
|-||field will contain between 1 and 100 '?' characters, inclusive.|