#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <cctype>
#include <tuple>
#include <climits>
#include <bitset>
#include <cassert>
#include <random>

#ifdef _MSC_VER
#include <agents.h>
#endif

#define FOR(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define REV(v) v.rbegin(), v.rend()
#define MEMSET(v, s) memset(v, s, sizeof(v))
#define UNIQUE(v) (v).erase(unique(ALL(v)), (v).end())
#define MP make_pair
#define MT make_tuple

using namespace std;

typedef long long ll;
typedef pair<int, int> P;

const int N = 1e5 + 10;
ll dp[N];

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n, v;
	cin >> n >> v;

	vector<ll> c(n);
	rep(i, n) cin >> c[i];

	partial_sum(ALL(c), c.begin());

	ll ans = c.back();
	v = max(0, v - n);

	rep(i, N) dp[i] = 1e18;
	dp[0] = 0;
	rep(i, n){
		int w = i + 1;
		rep(j, N - w){
			dp[j + w] = min(dp[j + w], dp[j] + c[i]);
		}
	}

	if (v < N){
		ans += dp[v];
	}
	else{
		ll vv = v - (N - 111);
		ll tmp = 1e18;
		rep(i, n){
			int w = i + 1;
			tmp = min(tmp, c[i] * (vv / w) + dp[N-111+vv%w]);
		}
		ans += tmp;
	}

	cout << ans << endl;


	return 0;
}