Description

From the $n$ digits starting from $1$ to $n$ ($1≤n≤9$), a total of $n!$ different permutations can be formed. Given one of these permutations, determine its lexicographical order among all permutations.

Input Format

The first line contains an integer $n$.
The second line contains an integer $x$, which is a permutation of the $n$ digits from $1$ to $n$.

Output Format

An integer representing the lexicographical order of the given permutation.

Sample

4
2143

8