#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

bool isKadomatsuSequence(int a, int b, int c){
    return a != b && b != c && c != a &&
        (max({a, b, c}) == b || min({a, b, c}) == b);
}

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int D[7];
    for(int i=0;i<7;++i){
        std::cin >> D[i];
    }

    int I[7];
    iota(I, I+7, 0);

    while(true){
        bool flag = true;
        
        for(int i=0;i+3<=7;++i){
            int a = D[I[i]],
                b = D[I[i+1]],
                c = D[I[i+2]];

            if(isKadomatsuSequence(a, b, c) && a < c){
                
            }else{
                flag = false;
            }
        }

        if(flag){
            std::cout << "YES" << std::endl;
            return 0;
        }
        
        if(!next_permutation(I, I+7)){
            break;
        }
    }

    std::cout << "NO" << std::endl;
}