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 int N = 2e5 + 5;
int a[N], id[N], l[N], r[N];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    id[a[i]] = i;
  }
  a[0] = a[n + 1] = 1e9;
  stack<int> s;
  s.push(0);
  for (int i = 1; i <= n; i++) {
    while (a[s.top()] < a[i]) s.pop();
    l[i] = s.top() + 1;
    s.push(i);
  }
  while (!s.empty()) s.pop();
  s.push(n + 1);
  for (int i = n; i >= 1; i--) {
    while (a[s.top()] < a[i]) s.pop();
    r[i] = s.top() - 1;
    s.push(i);
  }
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    if (i - l[i] < r[i] - i) {
      for (int j = l[i]; j < i; j++) {
        if (id[a[i] - a[j]] > i && id[a[i] - a[j]] <= r[i]) ans++;
      }
    } else {
      for (int j = i + 1; j <= r[i]; j++) {
        if (id[a[i] - a[j]] < i && id[a[i] - a[j]] >= l[i]) ans++;
      }
    }
  }
  cout << ans << '\n';
}
