#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
int n;
const int maxN = (int)1e7 + 10;
int nxt[maxN], prv[maxN];
int fenw[maxN];
void upd(int v, int d) {
    while (v <= n + 1) {
        fenw[v] += d;
        v = (v | (v - 1)) + 1;
    }
}
int get(int v) {
    int ans = 0;
    while (v > 0) {
        ans += fenw[v];
        v &= (v - 1);
    }
    return ans;
}
int upperBound(int sum) {
    int cur = 1;
    for (int i = 24; i >= 0; i--) {
        int ncur = cur + (1 << i) - 1;
        if (ncur <= n + 1 && fenw[ncur] <= sum) {
            sum -= fenw[ncur];
            cur = ncur + 1;
        }
    }
    return cur;
}
int main() {
    //freopen("input.txt", "r", stdin);
    ios_base::sync_with_stdio(false);
    //cin >> n;
    n = (int)1e7;
    vector < pair < int, int > > all;
    for (int i = 1; i <= n; i++) {
        //cin >> a[i];
        int x = i % 237 + 23 * i % 8;
        cin >> x;
        all.emplace_back(x, i);
    }
    sort(all.begin(), all.end());
    reverse(all.begin(), all.end());
    set < int > s;
    s.insert(0);
    s.insert(n + 1);
    ll ans = 0;
    nxt[0] = n + 1;
    prv[n + 1] = 0;
    nxt[n + 1] = n + 1;
    prv[0] = 0;
    upd(n + 1, 1);
    for (auto it : all) {
        int ind = it.second;
        int pos3 = upperBound(get(ind));
        int pos4 = nxt[pos3];
        int pos2 = prv[pos3];
        int pos1 = prv[pos2];
        nxt[pos2] = ind;
        prv[ind] = pos2;
        prv[pos3] = ind;
        nxt[ind] = pos3;
        upd(ind, 1);
        if (pos2 == 0 && pos3 == n + 1) continue;
        ans += 1LL * it.first * (pos4 - pos3) * (ind - pos2) + (pos2 - pos1) * (pos3 - ind);
    }
    cout << ans;
    return 0;
}