#include<bits/stdc++.h>
#include<fstream>
using namespace std;
#define MP make_pair
#define PB push_back
#define PF push_front
#define F first
#define S second
#define EPS 1e-9
#define MOD 1000000007
#define pi 3.14159265
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef pair<int,int> PII;
typedef long long int lli;
typedef unsigned long long int ULL;
#define endl '\n'
#define ip(n) scanf("%d",&n)
#define For(i,s,n) for(i=s;i<n;i++)
#define SYNC ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(NULL);
// Useful hardware instructions
#define bitcount __builtin_popcount
#define gcd __gcd
#define INF 99999999
#define SIZ 1010000
lli dp[5100][550],can[SIZ],n;
lli calc(int i,int sl,lli val,int ctr){
//cout<<i<<" "<<val<<" "<<endl;
if(i<n-1 && !sl)return INF;
if(i == n-1)return val*can[i]*(ctr+1);
if(dp[i][sl])return dp[i][sl];
dp[i][sl] = INF;
dp[i][sl] = min(calc(i+1,sl-1,1,0)+ val*can[i]*(ctr+1), calc(i+1,sl,val*can[i],ctr+1) );
cout<<i<<" "<<sl<<" "<<dp[i][sl]<<endl;
return dp[i][sl];
}
int main()
{
SYNC;
int i,x,y,k;
cin>>n>>k;
for(i=0;i<n;i++)cin>>can[i];
cout<<calc(0,k,1,0)<<endl;
// cout<<cnt<<endl;
}
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