#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <list>
#include <bitset>
#include <cmath>
#include <cstdio>
#include <map>

using namespace std;

inline bool kadomatu(int a,int b,int c){
    return a!=b&&b!=c&&c!=a&&((a<b && c<b)||(a>b && c>b));
}

int mat[3][3];

int main(){
	int i, j, k, l, m, n,x,y;
    
    vector<int> vi;
    
    for (i=0;i<7;i++){
        cin >> k;
        vi.push_back(k);
    }
    
    sort (vi.begin(),vi.end());
    
    do{
        for (i=0;i<5;i++){
            if (vi[i] >= vi[i+2] || !kadomatu(vi[i],vi[i+1],vi[i+2]))
                goto lb;
        }
        cout << "YES" << endl;
        return 0;
        lb:
        ;
    }while(next_permutation(vi.begin(),vi.end()));
    cout << "NO" << endl;
    return 0;
}