import times, strutils, sequtils, math, algorithm, tables, sets, lists, intsets
import critbits, future, strformat, deques,heapqueue
template `max=`(x,y) = x = max(x,y)
template `min=`(x,y) = x = min(x,y)
template `mod=`(x,y) = x = x mod y
template scan2 = (scan(), scan())
template scan3 = (scan(), scan())
let read* = iterator: string {.closure.} =
    while true: (for s in stdin.readLine.split: yield s)
proc scan(): int = read().parseInt
proc scanf(): float = read().parseFloat
proc toInt(c:char): int =
  return int(c) - int('0')



proc solve():string=
  var 
    n = 7
    a = newseqwith(n,scan())
  
  proc isIncKadomatsu():bool=
    for i in 0..<n-2:
      if a[i] < a[i+2] and ((a[i] > a[i+1] and a[i+1] < a[i+2]) or (a[i] < a[i+1] and a[i+1] > a[i+2])):
        continue
      else:
        return false
    return true

  a.sort()
  if isIncKadomatsu():
    return "YES"
  while a.nextPermutation:
    if isIncKadomatsu():
      return "YES"
  return "NO"


  


echo solve()