#include "bits/stdc++.h"
using namespace std;
#define MAX 25000

long long dp[MAX];

int main() {
	int N, V;
	cin >> N >> V;
	vector<long long> C(N);
	for (int i = 0; i < N; i++)
	{
		cin >> C[i];
	}
	int best = 0;
	for (int i = 1; i < N; i++)
	{
		C[i] += C[i - 1];
		if (C[i] * (best + 1) <= C[best] * (i + 1)){
			best = i;
		}
	}

	long long ans = 0;
	ans += C[N - 1];
	V -= N;

	if (V > 20000){
		long long skip = (V - 20000) / (best + 1);
		V -= skip * (best + 1);
		ans += skip * C[best];
	}
	for (int i = 0; i < MAX; i++)
	{
		dp[i] = (long long)2e18;
	}
	dp[0] = 0;

	for (int i = 0; i < V; i++)
	{
		for (int j = 0; j < N; j++)
		{
			if (i + j + 1 >= MAX) continue;
			dp[i + j + 1] = min(dp[i + j + 1], dp[i] + C[j]);
		}
	}
	ans += dp[V];
	cout << ans << endl;
	cin >> ans;
}