B. Nirvana
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

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 $n$.

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 $n$.

Examples
Input
390

Output
216

Input
7

Output
7

Input
1000000000

Output
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 $9^9=387420489$).