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;
struct Node {
  int x, id;
} b[N];
int n, a[N], pos[N], L[N], R[N], Stack[N], ans;
inline int read() {
  int x = 0, f = 0;
  char ch = getchar();
  while (!isdigit(ch)) f = ch == '-', ch = getchar();
  while (isdigit(ch)) x = (x << 3) + (x << 1) + ch - 48, ch = getchar();
  return f ? -x : x;
}
inline bool cmp(Node a, Node b) { return a.x > b.x; }
int main() {
  n = read();
  for (int i = 1; i <= n; i++) a[i] = read(), pos[a[i]] = i;
  int top = 0;
  for (int i = 1; i <= n; i++) {
    while (a[Stack[top]] < a[i] && top) top--;
    L[i] = Stack[top];
    Stack[++top] = i;
  }
  top = 0;
  Stack[0] = n + 1;
  for (int i = n; i >= 1; i--) {
    while (a[Stack[top]] < a[i] && top) top--;
    R[i] = Stack[top];
    Stack[++top] = i;
  }
  for (int i = 1; i <= n; i++) {
    if (i - L[i] <= R[i] - i) {
      for (int j = L[i] + 1; j < i; j++)
        if (pos[a[i] - a[j]] > i && pos[a[i] - a[j]] < R[i]) ans++;
    } else
      for (int j = i + 1; j < R[i]; j++)
        if (pos[a[i] - a[j]] < i && pos[a[i] - a[j]] > L[i]) ans++;
  }
  printf("%d\n", ans);
  return 0;
}
