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 = 100000;
const double pi = acos(-1.0);
int n, a[200200], pos[200200], l[200200], r[200200];
int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while ((ch < '0') || (ch > '9')) {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while ((ch >= '0') && (ch <= '9')) {
    x = x * 10 + (ch - '0');
    ch = getchar();
  }
  return x * f;
}
int main() {
  n = read();
  for (register int i = 1; i <= n; i++) {
    a[i] = read();
    pos[a[i]] = i;
  }
  a[0] = 1000000007;
  a[n + 1] = 1000000007;
  for (register int i = 1; i <= n; i++) {
    l[i] = i - 1;
    while (a[l[i]] < a[i]) l[i] = l[l[i]];
  }
  for (register int i = n; i >= 1; i--) {
    r[i] = i + 1;
    while (a[r[i]] < a[i]) r[i] = r[r[i]];
  }
  long long ans = 0;
  for (register int i = 1; i <= n; i++) {
    if (i - l[i] > r[i] - i) {
      for (register int j = i + 1; j <= r[i] - 1; j++) {
        int tmp = a[i] - a[j];
        if ((pos[tmp] >= l[i] + 1) && (pos[tmp] < i)) ans++;
      }
    } else {
      for (register int j = l[i] + 1; j <= i - 1; j++) {
        int tmp = a[i] - a[j];
        if ((pos[tmp] > i) && (pos[tmp] <= r[i] - 1)) ans++;
      }
    }
  }
  printf("%lld", ans);
  return 0;
}
