#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <queue>
#include <vector>
#include <list>
#include <string>
#include <iostream>
#include <ext/pb_ds/priority_queue.hpp>
using namespace std;
typedef long long LL;
LL dp[100][100][32];
LL num[100][100];
int main()
{
    freopen("cjzd.in", "r", stdin);
    freopen("cjzd.out", "w", stdout);
	int n, mk;
	cin >> n >> mk;
	string s;
	cin >> s;
	char *p = (char*)(s.c_str()-1);
	for(int i = 1; i <= n; i++)
		for(int j = i; j <= n; j++)
			for(int k = i; k <= j; k++)
				num[i][j] = num[i][j]*10 + p[k]-'0';		
	for(int i = 1; i <= n; i++)
		for(int j = i; j <= n; j++)
			dp[i][j][0] = num[i][j];
	for(int k = 1; k <= mk; k++)
		for(int i = 1; i <= n; i++)
			for(int j = i; j <= n; j++)
				for(int s = i; s < j; s++)
					dp[i][j][k] = max(dp[i][j][k], 
						dp[i][s][k-1]*num[s+1][j]);
	cout << dp[1][n][mk];
	return 0;
}