#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
  int d;
  vector<int> v;
  for(int i=0; i<7; ++i){
    cin>>d;
    v.push_back(d);
  }
  sort(v.begin(),v.end());
  string s="NO";
  do{
    int f=0;
    for(int i=0; i<v.size()-2; ++i){
      int a=v[i];
      int b=v[i+2];
      if(a>=b){
        f=1;
        break;
      }
    }
    if(f==1) continue;
    for(int i=1; i<v.size()-1; ++i){
      int a=v[i];
      int b=v[i-1];
      int c=v[i+1];
      if((a>b && a>c) || (a<b && a<c)){
        //
      } else {
        f=1;
        break;
      }
    }
    if(f==1) continue;
    s="YES";
    cout<<s<<endl;
    return 0;
  } while(next_permutation(v.begin(),v.end()));
  cout<<s<<endl;
  return 0;
}