import java.io.BufferedReader
import java.io.InputStream
import java.io.InputStreamReader
import java.lang.AssertionError
import java.util.*
import kotlin.collections.HashSet
import kotlin.math.abs
import kotlin.math.max
import kotlin.math.min

val MOD = 1_000_000_007

/**
 * 単調減少
 * [l, h) 方式
 * @return マッチするものがなかったらl
 */
inline fun findMax(l: Int, r: Int, f: (Int) -> Boolean): Int {
  var low = l
  var high = r + 1
  while(high - low > 1) {
    val m = (low + high) / 2
    if (f(m)) low = m
    else high = m
  }
  return low
}
data class Val(val i: Int, val a: Int) : Comparable<Val> {
  fun max(v: Val) = if (a > v.a) this else v
  fun min(v: Val) = if (a <= v.a) this else v
  override fun compareTo(v: Val): Int {
    if (a != v.a) return a.compareTo(v.a)
    return i.compareTo(v.i)
  }
}
data class Entry(val mx: Val, val mn1: Val, val mn2: Val?) {
  fun merge(e: Entry): Entry {
    val mns = HashSet<Val>()
    mns += mn1
    if (mn2 != null) mns += mn2
    mns += e.mn1
    if (e.mn2 != null) mns += e.mn2
    val sort = mns.toMutableList()
    sort.sort()
//    println(sort.take(2))
    return Entry(mx.max(e.mx), sort[0], if (sort.size >= 2) sort[1] else null)
  }

  fun merge0(e: Entry): Entry {
    var mn2 = this.mn1.max(e.mn1)
    if (this.mn2 != null) mn2 = mn2.min(this.mn2)
    if (e.mn2 != null) mn2 = mn2.min(e.mn2)
    return Entry(mx.max(e.mx), this.mn1.min(e.mn1), mn2)
  }
}
class Solver(stream: InputStream, private val out: java.io.PrintWriter) {
  private val reader = BufferedReader(InputStreamReader(stream), 32768)

  private val N = ni()
  private val A = na(N)

  fun solve() {
    val tbl = mutableListOf(Array(N){Entry(Val(it, A[it]), Val(it, A[it]), null)})
    var k = 1
    
    while (2 * k <= N) {
      val lst = tbl.last()
      val build = Array(N){lst[it]}
      for (i in 0 until N) {
        if (i + k < N) {
          build[i] = lst[i].merge0(lst[i + k])
        }
        else {
          build[i] = lst[i]
        }
      }
      tbl += build
      k *= 2
    }

    val n2k = IntArray(N + 1)
    val n2ksize = IntArray(N + 1)
    k = 1
    var ki = 0
    for (n in 1..N) {
      if (k * 2 == n) {
        k *= 2
        ki++
      }
      n2k[n] = ki
      n2ksize[n] = k
    }
    debug(n2k)
    debug(n2ksize)

    debug{"${tbl[1][2]}"}

    var ans = 0L
    for (i in 0 until N) {
      val len = findMax(1, N - i) { len ->
        val k = n2k[len]
        val ksize = n2ksize[len]
        var e = tbl[k][i]
        val j = len - ksize
        e = e.merge(tbl[k][i + j])
        e.mn2 != null && e.mn1.a + e.mn2!!.a >= e.mx.a
      }
      debug{"$i $len"}
      if (len > 1) ans += len - 1
    }
    out.println(ans)
  }













































  private val isDebug = try {
    // なんか本番でエラーでる
    System.getenv("MY_DEBUG") != null
  } catch (t: Throwable) {
    false
  }

  private var tokenizer: StringTokenizer? = null
  private fun next(): String {
    while (tokenizer == null || !tokenizer!!.hasMoreTokens()) {
      tokenizer = StringTokenizer(reader.readLine())
    }
    return tokenizer!!.nextToken()
  }

  private fun ni() = next().toInt()
  private fun nl() = next().toLong()
  private fun ns() = next()
  private fun na(n: Int, offset: Int = 0): IntArray {
    return IntArray(n) { ni() + offset }
  }
  private fun nal(n: Int, offset: Int = 0): LongArray {
    val res = LongArray(n)
    for (i in 0 until n) {
      res[i] = nl() + offset
    }
    return res
  }

  private fun na2(n: Int, offset: Int = 0): Array<IntArray> {
    val a  = Array(2){IntArray(n)}
    for (i in 0 until n) {
      for (e in a) {
        e[i] = ni() + offset
      }
    }
    return a
  }

  private inline fun debug(msg: () -> String) {
    if (isDebug) System.err.println(msg())
  }

  /**
   * コーナーケースでエラー出たりするので、debug(dp[1])のように添え字付きの場合はdebug{}をつかうこと
   */
  private inline fun debug(a: LongArray) {
    debug { a.joinToString(" ") }
  }

  private inline fun debug(a: IntArray) {
    debug { a.joinToString(" ") }
  }

  private inline fun debug(a: BooleanArray) {
    debug { toString(a) }
  }

  private inline fun toString(a: BooleanArray) = run{a.map { if (it) 1 else 0 }.joinToString("")}

  private inline fun debugDim(A: Array<LongArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }
  private inline fun debugDim(A: Array<IntArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }
  private inline fun debugDim(A: Array<BooleanArray>) {
    if (isDebug) {
      for (a in A) {
        debug(a)
      }
    }
  }

  /**
   * 勝手にimport消されるのを防ぎたい
   */
  private fun hoge() {
    min(1, 2)
    max(1, 2)
    abs(-10)
  }

  private inline fun assert(b: Boolean) = run{if (!b) throw AssertionError()}
}

fun main() {
  val out = java.io.PrintWriter(System.out)
  Solver(System.`in`, out).solve()
  out.flush()
}