#include<bits/stdc++.h>
using namespace std;
using ll=long long;

int main(){
    ll n, v;
    cin >> n >> v;
    vector<ll> a(n);
    for(auto &&val:a)cin >> val;
    ll ans = 1ll << 62, sumv = accumulate(a.begin(), a.end(), 0ll);
    if(v <= n){
        cout << sumv << endl;
        return 0;
    }
    for(int i = 0; i < n; i++){
        sumv -= a[i];
        ll sumv2 = 0, rem = v - (n - (i + 1));
        if(rem <= i + 1){
            for(int j = 0; j <= i; j++){
                sumv2 += a[j];
            }
        }else{
            for(int j = 0; j <= i; j++){
                sumv2 += a[j] * (rem / (i + 1) + (j < rem % (i + 1)));
            }
        }
        ans = min(ans, sumv + sumv2);
    }
    cout << ans << endl;
}