Nirvana

TE. Nirvana

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 $n$ ($1\le n\le 2\cdot 10^9$).

Output

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

Example

Input

390

Output

216

Note

In the first example the maximum product is achieved for $389$ (the product of digits is $3\cdot 8\cdot 9=216$).

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 $9^9=387420489$).

code

#include<bits/stdc++.h>
#define int long long
#define endl '\n'
 
using namespace std;


const int N = 110,INF=0x3f3f3f3f,mod=1e9+7;
 
typedef pair<int,int> PII;

int T=1;

int f(int a)
{
	if(a<10){
		return max(a,(int)1);
	}
	return max(a%10*f(a/10), f(a/10-1)*9);
}

void solve(){
	int n;
	cin>>n;
	cout<<f(n)<<endl;
}

signed main(){
//	cin>>T; 
    while(T--){
        solve();
    }
    return 0;
}