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;
template <typename A, typename B>
string to_string(pair<A, B> p);
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);
string to_string(const string& s) { return '"' + s + '"'; }
string to_string(const char* s) { return to_string((string)s); }
string to_string(bool b) { return (b ? "true" : "false"); }
string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}
template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}
template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto& x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ")";
}
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " +
         to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
const long long mod = 1e9 + 7;
long long power(long long a, long long b, long long m = mod) {
  if (b < 0) {
    return power(power(a, -b), mod - 2);
  }
  long long x = 1;
  while (b) {
    if (b & 1) {
      x = 1ll * x * a % m;
    }
    a = 1ll * a * a % m;
    b /= 2;
  }
  return x;
}
const int INT_INF = 1e9 + 9;
const long long LL_INF = 2e18;
const int N = 3e5 + 9;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  vector<int> a(n), pos(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    a[i]--;
    pos[a[i]] = i;
  }
  vector<int> st;
  vector<int> pge(n, -1), nge(n, n);
  for (int i = 0; i < n; i++) {
    while (!st.empty() && a[st.back()] < a[i]) st.pop_back();
    if (!st.empty()) pge[i] = st.back();
    st.push_back(i);
  }
  st.clear();
  for (int i = n - 1; i >= 0; i--) {
    while (!st.empty() && a[st.back()] < a[i]) st.pop_back();
    if (!st.empty()) nge[i] = st.back();
    st.push_back(i);
  }
  int ans = 0;
  for (int i = 0; i < n; i++) {
    int l = pge[i] + 1, r = nge[i] - 1;
    if (i - l > r - i) {
      for (int j = i + 1; j <= r; j++) {
        int need = a[i] - a[j] - 1;
        if (pos[need] >= l && pos[need] < i) {
          ans += 1;
        }
      }
    } else {
      for (int j = l; j < i; j++) {
        int need = a[i] - a[j] - 1;
        if (pos[need] > i && pos[need] <= r) {
          ans += 1;
        }
      }
    }
  }
  cout << ans << "\n";
  return 0;
}
