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 id[N], a[N], n;
int st[N], pre[N], suf[N];
int main() {
  scanf("%d", &n);
  for (register int i = 1; i <= n; ++i) {
    scanf("%d", &a[i]);
    id[a[i]] = i;
  }
  int r = 0;
  for (register int i = 1; i <= n; ++i) {
    while (r > 0 && a[st[r]] < a[i]) r--;
    pre[i] = st[r] + 1;
    st[++r] = i;
  }
  r = 0;
  st[0] = n + 1;
  for (int i = n; i; i--) {
    while (r > 0 && a[st[r]] < a[i]) r--;
    suf[i] = st[r] - 1;
    st[++r] = i;
  }
  int ans = 0;
  for (register int i = 1; i <= n; ++i) {
    if (i - pre[i] < suf[i] - i) {
      for (int j = pre[i]; j < i; j++) {
        if (id[a[i] - a[j]] > i && id[a[i] - a[j]] <= suf[i]) ans++;
      }
    } else {
      for (int j = suf[i]; j > i; j--) {
        if (id[a[i] - a[j]] < i && id[a[i] - a[j]] >= pre[i]) ans++;
      }
    }
  }
  cout << ans;
  return 0;
}
