#P1143B. Nirvana

    ID: 4621 Type: RemoteJudge 1000ms 256MiB Tried: 0 Accepted: 0 Difficulty: 4 Uploaded By: Tags>brute forcemathnumber theory*1200

Nirvana

Description

Kurt reaches nirvana when he finds the product of all the digits of some positive integer. Greater value of the product makes the nirvana deeper.

Help Kurt find the maximum possible product of digits among all integers from $1$ to $n$.

The only input line contains the integer $n$ ($1 \le n \le 2\cdot10^9$).

Print the maximum product of digits among all integers from $1$ to $n$.

Input

The only input line contains the integer $n$ ($1 \le n \le 2\cdot10^9$).

Output

Print the maximum product of digits among all integers from $1$ to $n$.

390
7
1000000000
216
7
387420489

Note

In the first example the maximum product is achieved for $389$ (the product of digits is $3\cdot8\cdot9=216$).

In the second example the maximum product is achieved for $7$ (the product of digits is $7$).

In the third example the maximum product is achieved for $999999999$ (the product of digits is $9^9=387420489$).