#include <bits/stdc++.h>

#define _overload(_1,_2,_3,name,...) name
#define _rep(i,n) _range(i,0,n)
#define _range(i,a,b) for(int i=int(a);i<int(b);++i)
#define rep(...) _overload(__VA_ARGS__,_range,_rep,)(__VA_ARGS__)

#define _rrep(i,n) _rrange(i,n,0)
#define _rrange(i,a,b) for(int i=int(a)-1;i>=int(b);--i)
#define rrep(...) _overload(__VA_ARGS__,_rrange,_rrep,)(__VA_ARGS__)

#define _all(arg) begin(arg),end(arg)
#define uniq(arg) sort(_all(arg)),(arg).erase(unique(_all(arg)),end(arg))
#define getidx(ary,key) lower_bound(_all(ary),key)-begin(ary)
#define clr(a,b) memset((a),(b),sizeof(a))
#define bit(n) (1LL<<(n))
#define popcount(n) (__builtin_popcountll(n))

template<class T>bool chmax(T &a, const T &b) { return (a<b)?(a=b,1):0;}
template<class T>bool chmin(T &a, const T &b) { return (b<a)?(a=b,1):0;}

using namespace std;

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

bool check(int a,int b,int c){
	if(a==b) return false;
	if(b==c) return false;
	if(c==a) return false;

	if(min({a,b,c})==b) return true;
	if(max({a,b,c})==b) return true;

	return false;
}


int main(void){
	const int n=7;
	vector<int> d(n);
	rep(i,n) cin >> d[i];
	sort(_all(d));

	bool ok=false;

	do{
		bool all=true;
		rep(i,1,n-1) if(check(d[i-1],d[i],d[i+1])==false) all=false;
		ok|=all; 
	}while(next_permutation(_all(d)));

	if(ok)
		puts("YES");
	else
		puts("NO");

	return 0;
}