package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	n := 7
	dd := make([]int, n)
	for i := 0; i < n; i++ {
		dd[i] = getNextInt(scanner)
	}
	aa := make([]int, n)
	ans := false
	var dfs func(i int, used uint32)
	dfs = func(i int, used uint32) {
		if i == n {
			ok := func() bool {
				for i := 0; i < n-2; i++ {
					if kadomatu(dd[aa[i]], dd[aa[i+1]], dd[aa[i+2]]) == false {
						return false
					}
				}
				return true
			}
			if ok() {
				ans = true
				return
			}
		}
		for j := 0; j < n; j++ {
			if used>>uint(j)&1 == 1 {
				continue
			}
			aa[i] = j
			dfs(i+1, used|1<<uint(j))
		}
	}
	dfs(0, 0)
	if ans {
		fmt.Fprintln(writer, "YES")
		return
	}
	fmt.Fprintln(writer, "NO")
}
func kadomatu(a, b, c int) bool {
	return a < c && (a > b && b < c || a < b && b > c)
}