// author : HuuHung
// 25.3.2024


#include <bits/stdc++.h>
#define ii pair <int, int>
#define F first
#define S second
#define ll long long
#define lb long double
#define pb push_back
#define vi vector <int>
#define vll vector <ll>
#define Bit(x, i) ((x) >> (i) & 1)
#define Mask(i) (1ll << (i))
#define All(v) (v).begin(), (v).end()

using namespace std;

void maxzi(auto &a, auto b){
    a = max(a, b);
}

void minzi(auto &a, auto b){
    a = min(a, b);
}

const int N = 5e5 + 5;
const int mod = 1e9 + 7;
const int LG = 20;

void add(auto &a, auto b){
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

auto Pow(auto a, auto b){
    if (b == 0) return 1;
    if (b % 2) return 1ll * a * Pow(a, b - 1) % mod;
    auto c = Pow(a, b / 2);
    return 1ll * c * c % mod;
}

// * end

const ll inf = 1e18;

ll h[N];

void solve(){
    int n; cin >> n ;
    for (int i = 1; i <= n; ++ i) cin >> h[i];
    int ans = 0;
    for (int i = 1; i <= n; ++ i){
        int ed = n;
        ll L = 0;
        ll R = inf;
        for (int j = i + 1; j <= n; ++ j){
            if (h[j] >= h[j - 1] && h[j] >= h[j + 1]){
                maxzi(L, h[j] + min(h[j - 1], h[j + 1]) + 1);
            }
            if (h[j] <= h[j - 1] && h[j] <= h[j + 1]){
                minzi(R, h[j] + max(h[j - 1], h[j + 1]) - 1);
            }
            if (L > R){
                ed = j;
                break;
            }
        }
        ans += ed - i ;
    }
    cout << ans;
}


int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    while (t --) solve();

    return 0;
}