When a piece of paper is folded in half, its thickness doubles. You have a piece of paper with a thickness of 1 cm. You want the paper to have a thickness of at least n cm. How many times you need to fold the paper at least to achieve this?
### Input
- A line containing an integer n.
### Output
- Print an integer which is the minimum number of folds.
### Constraints
- 1≤n≤1018.
### Sample test
7
Output:
3
