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;
int n;
const int maxn = 2e5 + 5;
int p[maxn];
int inv[maxn];
int l[maxn], r[maxn];
int st[maxn], tot;
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    scanf("%d", &p[i]);
    inv[p[i]] = i;
  }
  tot = 0;
  for (int i = 1; i <= n; i++) {
    while (tot > 0 && p[st[tot]] <= p[i]) tot--;
    if (tot == 0)
      l[i] = 1;
    else
      l[i] = st[tot] + 1;
    st[++tot] = i;
  }
  tot = 0;
  for (int i = n; i >= 1; i--) {
    while (tot > 0 && p[st[tot]] <= p[i]) tot--;
    if (tot == 0)
      r[i] = n;
    else
      r[i] = st[tot] - 1;
    st[++tot] = 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++) {
        int val = p[i] - p[j];
        if (inv[val] > i && inv[val] <= r[i]) {
          ans++;
        }
      }
    } else {
      for (int j = i + 1; j <= r[i]; j++) {
        int val = p[i] - p[j];
        if (inv[val] >= l[i] && inv[val] < i) {
          ans++;
        }
      }
    }
  }
  cout << ans << endl;
  return 0;
}
