#include <bits/stdc++.h>
using namespace std;
bool isincreaseKadomatsu(int a,int b,int c){
    if(a >= c)return false;
    if(a>b && b<c)return true;
    if(a<b && b>c)return true;
    return false;
}

int main() {
    vector<int> A(7);
    for(int i = 0; i < 7; i++)
        cin >> A[i];
    vector<int> id(7);
    iota(id.begin(),id.end(),0);
    do{
        if([&](){
            for(int i = 0; i < 5; i++)
                if(isincreaseKadomatsu(A[id[i]],A[id[i+1]],A[id[i+2]])==false)return false;
            return true;
        }()){
            cout << "YES" << endl;
            return 0;
        }
    }while(next_permutation(id.begin(),id.end()));
    cout << "NO" << endl;
    return 0;
}