#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int D[7];

int main(){
    while(cin >> D[0]){
        rep(i, 6)cin >> D[i + 1];
        sort(D, D + 7);
        int ok = 0;
        do{
            ok = 1;
            rep(i, 5){
                if(D[i] >= D[i + 2] || D[i] == D[i + 1] || D[i + 1] == D[i + 2]
                   || (max({D[i],D[i + 1],D[i + 2]}) != D[i + 1] && min({D[i], D[i + 1], D[i + 2]}) != D[i + 1]))
                    ok = 0;
            }
            if(ok)break;
        } while(next_permutation(D, D + 7));
        puts(ok ? "YES" : "NO");
    }
}