#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <cstring>
#include <queue>
#define maxn 45
using namespace std;
long long f[maxn][maxn],dp[maxn][maxn];
int main(){
	freopen("cjzd.in","r",stdin);
	freopen("cjzd.out","w",stdout);
	int n,k;
	cin>>n>>k;
	for(int i=1;i<=n;i++){
		char a;
		cin>>a;
		f[i][i]=a-'0';
	}
	for(int i=1;i<=n;i++){
		for(int j=i+1;j<=n;j++){
			f[i][j]=f[i][j-1]*10+f[j][j];
		}
	}
	for(int i=1;i<=n;i++){
		dp[i][0]=f[1][i];
	}
	for(int p=1;p<=k;p++){
		for(int i=p+1;i<=n;i++){
			for(int j=1;j<i;j++){
				if(dp[j][p-1]>0){
					//cout<<dp[i][p]<<" "<<f[j+1][i]<<" ";
					dp[i][p]=max(dp[i][p],dp[j][p-1]*f[j+1][i]);
					//cout<<dp[i][p]<<endl;
				}
			}
		}
	}
	cout<<dp[n][k];
}