// #pragma GCC target("avx2,avx512f,avx512vl,avx512bw,avx512dq,avx512cd,avx512vbmi,avx512vbmi2,avx512vpopcntdq,avx512bitalg,bmi,bmi2,lzcnt,popcnt")
// #pragma GCC optimize("Ofast")

#include<bits/stdc++.h>
using namespace std;
#define int long long

int dp[105][20005];
int n,m;
int arr[105];

int solve(int idx, int rem) {
    if (idx >= n)return 0;

    auto& ret = dp[idx][rem];
    if (ret != -1)return ret;

    double d = rem;
    d /= 3;
    d *= 2;
    int nw = d;
    //cout << rem << "\n";
    ret = solve(idx + 1, nw) + min(rem, arr[idx]);
    
    ret = max({ret,solve(idx + 1, rem),solve(idx + 2, m) });
    //for (int i = idx + 3; i < n; i++)ret = max(ret, solve(i, m));


    return ret;
}

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

    memset(dp, -1, sizeof(dp));
    cin >> n >> m;

    for (int i = 0; i < n; i++)cin >> arr[i];

    cout << solve(0, m)<<"\n";
}