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>
const double esp = 1e-6;
const double pi = acos(-1.0);
const int INF = 0x3f3f3f3f;
const int inf = 1e9;
using namespace std;
int read() {
  char ch = getchar();
  int x = 0, f = 1;
  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;
}
const int N = 2e5 + 10;
int a[N];
int pos[N];
int lf[N];
int rt[N];
int n;
int main() {
  n = read();
  for (int i = 1; i <= n; i++) {
    a[i] = read();
    pos[a[i]] = i;
  }
  stack<int> st;
  for (int i = 1; i <= n; i++) {
    while (st.size() && a[st.top()] < a[i]) {
      st.pop();
    }
    if (st.size()) {
      lf[i] = st.top() + 1;
    } else
      lf[i] = 1;
    st.push(i);
  }
  while (!st.empty()) st.pop();
  for (int i = n; i >= 1; i--) {
    while (st.size() && a[st.top()] < a[i]) {
      st.pop();
    }
    if (st.size())
      rt[i] = st.top() - 1;
    else
      rt[i] = n;
    st.push(i);
  }
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    int templ = i - lf[i];
    int tempr = rt[i] - i;
    if (templ < tempr) {
      for (int j = lf[i]; j <= i - 1; j++) {
        int temp = pos[a[i] - a[j]];
        if (temp > i && temp <= rt[i]) {
          ans++;
        }
      }
    } else {
      for (int j = i + 1; j <= rt[i]; j++) {
        int temp = pos[a[i] - a[j]];
        if (temp < i && temp >= lf[i]) ans++;
      }
    }
  }
  cout << ans << endl;
  return 0;
}
