#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

bool isKadomatsu(int a, int b, int c){
    if(a < c){
        if( (a < b && b > c) || (a > b && b < c) ){
            return true;
        }
    }
    return false;
}

int main(){
    int N = 7;
    vector<int> A(N);
    for(int i=0;i<N;i++){
        cin >> A[i];
    }

    sort(A.begin(), A.end());

    do{
        bool flag = true;
        for(int i=0;i<N-2;i++){
            if(!isKadomatsu(A[i], A[i+1], A[i+2])){
                flag = false;
            }
        }
        if(flag){
            cout << "YES" << endl;
            return 0;
        }
    }while(next_permutation(A.begin(), A.end()));

    cout << "NO" << endl;
    return 0;
}