In 1850, the Reverend Thomas P. Kirkman, a clergyman of the Church of England, proposed an interesting problem known as the schoolgirl walking problem. In a certain girls' school, there were $15$ schoolgirls in a group. They went for a walk outside the school every day. To strengthen their mutual understanding and promote friendship, Kirkman envisioned that if the girls were appropriately divided into $5$ groups of $3$ girls each, such that every girl could be in the same group with every other girl exactly once within $7$ days, how should they be grouped to achieve this?
This seemingly simple problem has an unusual grouping algorithm, which later became known as the Kirkman's schoolgirl problem. Over a hundred years later, many other interesting grouping algorithms for schoolgirl walks were invented. One such interesting random circular grouping algorithm is described as follows:
Suppose there are $n$ schoolgirls to be grouped. First, randomly assign a unique number to each girl. The set of numbers for these $n$ girls is exactly $[1, n]$. Girls in the same group can freely sit in a circle on the grass. Each girl in the circle must satisfy the condition that the product of her number and the numbers of her two neighbors is less than $n$. When there is only one girl in the circle, her own number must be less than $n$. Girls who satisfy the above conditions are placed in one group. The remaining girls continue to be grouped using this method.
Schoolgirl Walking Problem: For a given integer $n$, calculate the maximum number of girls that can be placed in the same group.
Input
The input contains multiple test cases. Each line contains an integer $n$, representing the number of schoolgirls to be grouped.
Output
For each test case $n$ in the input file, output the maximum number of girls that can be placed in the same group. Each result should be printed on a new line.
Examples
Input 1
2
3
5
7
8
Output 1
1
2
2
3
3
Subtasks
| Test Case ID | $n$ |
|---|---|
| $1 \sim 5$ | $n \leq 600\,000$ |
| $6 \sim 8$ | $n \leq 50\,000\,005$ |
| $9 \sim 10$ | $n \leq 1\,000\,000\,000$ |
Note
- The number of test cases was not provided during the contest; "participants should evaluate this themselves."
- The description in the problem is ambiguous, but no clarification was provided during the contest.