def main1(n,a):
  inf=10**10
  def f(x,y):
    ary=[]
    xidx,yidx=0,0
    while len(ary)<2:
      if x[xidx]<y[yidx]:
        ary.append(x[xidx])
        xidx+=1
      else:
        ary.append(y[yidx])
        yidx+=1
    ary.append(max(x[-1],y[-1]))
    return ary
  st=SegmentTree(n,f,default=[inf,inf,0])
  for i,x in enumerate(a):
    st.update(i,[x,inf,x])
  ans=0
  l=0
  tmp={}
  M,m1,m2=-1,-1,-1
  for i in range(n-1):
    if 0<i and a[i-1] not in tmp:
      ans+=(l-i)
      continue
    l,r=l,n
    while r-l>1:
      x=(l+r)//2
      m1,m2,M=st.query(i,x+1)
      if M<=m1+m2:
        l,r=x,r
      else:
        l,r=l,x
    ans+=(l-i)
    tmp={M,m1,m2}
  return ans

if __name__=='__main__':
  n=int(input())
  a=list(map(int,input().split()))
  #ret0=main0(n,a)
  ret1=main1(n,a)
  #print(ret0)
  print(ret1)