9792: ABC263 —— B - Ancestor
[Creator : ]
Description
There are $N$ people, called Person $1$, Person $2$, $\ldots$, Person $N$.
The parent of Person $i$ $(2 \le i \le N)$ is Person $P_i$. Here, it is guaranteed that $P_i < i$.
How many generations away from Person $N$ is Person $1$?
The parent of Person $i$ $(2 \le i \le N)$ is Person $P_i$. Here, it is guaranteed that $P_i < i$.
How many generations away from Person $N$ is Person $1$?
Input
Input is given from Standard Input in the following format:
```
$N$
$P_2$ $P_3$ $\dots$ $P_N$
```
```
$N$
$P_2$ $P_3$ $\dots$ $P_N$
```
Output
Print the answer as a positive integer.
Constraints
- $2 \le N \le 50$
- $1 \le P_i < i(2 \le i \le N)$
- All values in input are integers.
- $1 \le P_i < i(2 \le i \le N)$
- All values in input are integers.
Sample 1 Input
3
1 2
Sample 1 Output
2
Person 2 is a parent of Person 3, and thus is one generation away from Person 3.
Person 1 is a parent of Person 2, and thus is two generations away from Person 3.
Therefore, the answer is 2.
Sample 2 Input
10
1 2 3 4 5 6 7 8 9
Sample 2 Output
9