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 + 10;
int a[N], st[N], be[N], ed[N], mk[N];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 1; i <= n; ++i) scanf("%d", &a[i]);
  int head = 1, tail = 0;
  for (int i = 1; i <= n; ++i) {
    while (tail >= head && a[st[tail]] < a[i]) tail--;
    if (tail >= head)
      be[i] = st[tail] + 1;
    else
      be[i] = 1;
    st[++tail] = i;
  }
  head = 1, tail = 0;
  for (int i = n; i >= 1; --i) {
    while (tail >= head && a[st[tail]] < a[i]) tail--;
    if (tail >= head)
      ed[i] = st[tail] - 1;
    else
      ed[i] = n;
    st[++tail] = i;
  }
  int ans = 0;
  for (int i = 1; i <= n; ++i) mk[a[i]] = i;
  for (int i = 1; i <= n; ++i) {
    int l = (i - be[i]), r = (ed[i] - i);
    if (l >= r) {
      for (int j = i + 1; j <= ed[i]; ++j) {
        if (a[i] != a[j] * 2 && mk[a[i] - a[j]] >= be[i] && mk[a[i] - a[j]] < i)
          ans++;
      }
    } else {
      for (int j = be[i]; j <= i - 1; ++j) {
        if (a[i] != a[j] * 2 && mk[a[i] - a[j]] > i && mk[a[i] - a[j]] <= ed[i])
          ans++;
      }
    }
  }
  printf("%d\n", ans);
  return 0;
}
