/*****************************************
Note  : 
******************************************/
#include <queue>
#include <math.h>
#include <stack>
#include <stdio.h>
#include <iostream>
#include <string.h>
#include <algorithm>
using namespace std;
#define LL long long
const int N = 100 + 10;
const int INF = 0x3f3f3f3f;
struct node
{
	int a[N];
	node()
	{
		memset(a,0,sizeof(a));
	}
	void operator = (const node &s)
	{
		memcpy(a,s.a,sizeof(s.a));
	}
	node operator + (const int &s)
	{
		node t;
		t.a[0] += s;
		for(int i = 0 ; i < 50 ; i++)
		{
			t.a[i] += a[i];
			t.a[i+1] += t.a[i]/10;
			t.a[i] %= 10;
		}
		return t;
	}
	node operator + (const node &s)
	{
		node t;
		for(int i = 0 ; i <= 50 ; i++)
		{
			t.a[i] += a[i] + s.a[i];
			t.a[i+1] += t.a[i]/10;
			t.a[i] %= 10;
		}
		return t;
	}
	node operator * (const node &s)
	{
		node t;
		for(int i = 0 ; i < 50 ; i++)
			for(int j = 0 ; j < 50 ; j++)
			{
				t.a[i+j] += a[i] * s.a[j];
				t.a[i+j+1] += t.a[i+j]/10;
				t.a[i+j] %= 10;
			}
			return t;
	}
	node operator << (const int &s)
	{
		node t;
		for(int i = 50 ; i >= 0 ; i--)
			t.a[i+s] = a[i];
		return t;
	}
	bool operator < (const node &s)
	{
		for(int i = 50 ; i >= 0 ; i--)
			{
				if(a[i] < s.a[i])	return true;
				else if(a[i] > s.a[i])	return false;
			}
			return false;
	}
	void print()
	{
		int len = N - 1;
		while(a[len] == 0 && len > 0)
			len--;
		for(int i = len ; i >= 0 ; i--)
			cout << a[i];
		cout << endl;
	}
};
int n , k;
char num[100];
node x , sum[N][N] , dp[N][N];
int main()
{
	cin >> n >> k;
	cin >> num;
	for(int i = 0 ; i < n ; i++)
		x.a[i] = num[i] - '0';
	for(int i = 0 ; i < n ; i++)
		for(int j = i ; j < n ; j++)
			if(i == j)
				sum[i][j].a[0] = x.a[j];
			else
				sum[i][j] = (sum[i][j-1] << 1) + x.a[j];

	for(int i = 0 ; i <= k ; i++)
		for(int j = 0 ; j <= n ; j++)
			dp[j][i].a[0] = 1;

	for(int i = 0 ; i < n ; i++)
		dp[i][0] = sum[0][i];

	for(int l = 1 ; l <= k ; l++)
		for(int i = l ; i < n ; i++)
			for(int j = l-1 ; j < i ; j++)
				if(dp[i][l] < dp[j][l-1] * sum[j+1][i])
					dp[i][l] = dp[j][l-1] * sum[j+1][i];

	dp[n-1][k].print();
    return 0;
}
```c