Description

The initial height of the bamboo shoot is $0$, and its growth rate decreases with each day: it grows $16$ centimeters on the first day, $8$ centimeters on the second day, and so on, with the growth on the $n$-th day being $\frac{16}{n}$ centimeters (the daily growth may not be an integer). The bamboo shoot can be harvested and sold when it reaches a height of $k$ centimeters or more. On which day can the farmer harvest the bamboo shoot?
If the bamboo shoot still cannot reach the harvest height after one year (after the $365$-th day), output $-1$.

Input Format

Input consists of a single line containing an integer $k$ ($1≤k≤120$), representing the minimum height at which the bamboo shoot can be harvested.

Output Format

Output a single line containing an integer, representing the day after which the bamboo shoot can be harvested.

Sample

10

1