#include <algorithm>
#include <iostream>

using namespace std;

const long long INF = 1000000000000000001l;

int N, V;
long long C[100];
long long cost[10101];

int main() {
	cin >> N >> V;
	long long res = 0;
	for (int i = 0; i < N; i++) {
		cin >> C[i];
		res += C[i];
		if (i > 0) {
			C[i] += C[i - 1];
		}
	}
	V -= N;
	for (int c = 0; c <= 10100; c++) {
		cost[c] = INF;
	}
	cost[0] = 0;
	for (int c = 0; c <= 10100; c++) {
		for (int i = 0; i < N; i++) {
			int cc = c + i + 1;
			if (cc <= 10100) {
				cost[cc] = min(cost[cc], cost[c] + C[i]);
			}
		}
	}
	int v = 0;
	for (int i = 1; i < N; i++) {
		if (C[i] * (v + 1) < C[v] * (i + 1)) {
			v = i;
		}
	}
	int n = max(0, (V - 10000) / (v + 1));
	V -= n * (v + 1);
	res += n * C[v] + cost[V];
	cout << res << endl;
	return 0;
}