Lake with lilies#2059
In the forest lake, lilies have started to bloom. On the first day, a single lily bloomed, and every subsequent day the number of blooming lilies doubled. On the -th day, the entire lake surface was covered with blooming lilies. On which day was half of the lake's surface covered with blooming lilies?
The number (1 < n \leq 200), the day on which the whole lake surface was covered with blooming lilies.
Print the number of the day when half of the lake surface was covered with blooming lilies.
Example 1