#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
 
using namespace std;
 
#define sz size()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(c) (c).begin(), (c).end()
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define clr(a, b) memset((a), (b) ,sizeof(a))
 
#define MOD 1000000009

int isKadomatsu(int a, int b, int c){
  if((a<b&&a>c)||(a>b&&a<c)||(c<a&&c>b)||(c>a&&c<b))return 1;
  return 0;
}

int main(){
  vector<int> v;
  rep(i,0,7){
    int a;
    cin>>a;
    v.pb(a);
  }
  sort(all(v));
  do{
    if(v[0]<v[2]&&v[1]<v[3]&&v[2]<v[4]&&v[3]<v[5]&&v[4]<v[6]){
      int flag = 1;
      rep(i,0,v.sz-2){
        if(isKadomatsu(v[i],v[i+1],v[i+2])==0){
          flag = 0;
        }
      }
      if(flag == 1){
        cout << "YES" << endl;
        return 0;
      }
    }
  }while(next_permutation(all(v)));
  cout << "NO" << endl;
  return 0;
}