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].
n = int(input())
a = list(map(int, input().split()))

p = list(range(n + 1))
s = [set() for i in range(n + 1)]

def find(x):
    if p[x] != x:
        p[x] = find(p[x])
    return p[x]

def union(x, y, cur):
    x, y = find(x), find(y)
    r = 0
    if len(s[x]) < len(s[y]):
        x, y = y, x
    for k in s[y]:
        r += cur - k in s[x]
    s[x] |= s[y]
    s[x].add(cur)
    p[y] = x
    return r

print(sum(union(i, i + 1, a[i]) for i in sorted(range(n), key=lambda i: a[i])))