#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <map>
#define for(i,x,n) for(int i=x;i<n;i++)
#define ll long long int
#define INF 0x3f3f3f3f
#define MOD 1000000007using namespace std;int a[15];//0为*,1为＋
int num[15];
int m[15];//待乘
int n,k;
int maxx=0;int sum(){int i=0;if(a[1]==0){m[i++]=num[0];m[i]=num[1];for(j,2,n){if(a[j]==1){m[i]+=num[j];}if(a[j]==0){m[++i]=num[j];}}int ans=1;for(j,0,i+1){ans*=m[j];}return ans;}if(a[1]==1){m[i]=num[0];m[i]+=num[1];for(j,2,n){if(a[j]==1){m[i]+=num[j];}if(a[j]==0){m[++i]=num[j];}}int ans=1;for(j,0,i+1){ans*=m[j];}return ans;}}void dfs(int pos,int mul,int add){if(pos==n&&mul==0&&add==0){maxx=max(maxx,sum());}else if(pos!=n){if(mul>0&&add==0){a[pos]=0;dfs(pos+1,mul-1,add);}if(mul==0&&add>0){a[pos]=1;dfs(pos+1,mul,add-1);}if(mul>0&&add>0){a[pos]=0;dfs(pos+1,mul-1,add);a[pos]=1;dfs(pos+1,mul,add-1);}}
}int main()
{scanf("%d %d",&n,&k);for(i,0,n){scanf("%d",&num[i]);}dfs(1,k,n-k-1);//放的位置，乘号剩余，加号剩余printf("%d",maxx);return 0;
}

#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <map>
#define for(i,x,n) for(int i=x;i<n;i++)
#define ll long long int
#define INF 0x3f3f3f3f
#define MOD 1000000007using namespace std;int a[15];//0为*,1为＋
ll num[15];
ll m[15];//待乘
ll n,k;
ll maxx=0;ll sum(){int i=0;if(a[1]==0){m[i++]=num[0];m[i]=num[1];for(j,2,n){if(a[j]==1){m[i]+=num[j];}if(a[j]==0){m[++i]=num[j];}}ll ans=1;for(j,0,i+1){ans*=m[j];}return ans;}if(a[1]==1){m[i]=num[0];m[i]+=num[1];for(j,2,n){if(a[j]==1){m[i]+=num[j];}if(a[j]==0){m[++i]=num[j];}}ll ans=1;for(j,0,i+1){ans*=m[j];}return ans;}}void dfs(int pos,int mul,int add){if(pos==n&&mul==0&&add==0){if(maxx<sum()){maxx=sum();}//maxx=max(maxx,sum());}else if(pos!=n){if(mul>0&&add==0){a[pos]=0;dfs(pos+1,mul-1,add);}if(mul==0&&add>0){a[pos]=1;dfs(pos+1,mul,add-1);}if(mul>0&&add>0){a[pos]=0;dfs(pos+1,mul-1,add);a[pos]=1;dfs(pos+1,mul,add-1);}}
}int main()
{scanf("%d %d",&n,&k);for(i,0,n){scanf("%d",&num[i]);}dfs(1,k,n-k-1);//放的位置，乘号剩余，加号剩余printf("%lld",maxx);return 0;
}