You are given a permutation p of n integers 1, 2, ..., n (a permutation is an array where each element from 1 to n occurs exactly once).

Let's call some subsegment p[l, r] of this permutation special if p_l + p_r = max _{i = l}^{r} p_i. Please calculate the number of special subsegments.

Input

The first line contains one integer n (3 ≤ n ≤ 2 ⋅ 10^5).

The second line contains n integers p_1, p_2, ..., p_n (1 ≤ p_i ≤ n). All these integers are pairwise distinct.

Output

Print the number of special subsegments of the given permutation.

Examples

Input


5
3 4 1 5 2


Output


2


Input


3
1 3 2


Output


1

Note

Special subsegments in the first example are [1, 5] and [1, 3].

The only special subsegment in the second example is [1, 3].
#include <bits/stdc++.h>
using namespace std;
const long long mk = 200005;
const long long logn = 29;
const long long mod = 1e9 + 7;
set<int> T[4 * mk];
int mx[4 * mk], n;
int ans = 0, a[mk];
int Node[4 * mk];
int init() {
  cin >> n;
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (int i = 1; i <= n; i++) {
    if (a[i] < a[i + 1] || a[i] < a[i - 1]) continue;
    set<int> cur;
    for (int j = i - 1; a[j] < a[i] && j >= 1; j--) cur.insert(a[j]);
    for (int j = i + 1; a[j] < a[i] && j <= n; j++)
      if (cur.count(a[i] - a[j])) ans++;
  }
  return ans;
}
signed main() { cout << init(); }
