#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)

typedef vector<int> vi;

bool check(vi _a)
{
	vi a(3);
	rep(i, 0, 3) a[i] = _a[i];
	
	//rep(i, 0, 3) cout << a[i] << " ";
	//cout << endl;

	if (a[0] == a[1]) return false;
	if (a[0] == a[2]) return false;
	if (a[1] == a[2]) return false;
	if (a[2] < a[0]) return false;

	int _max = max(a[0], max(a[1], a[2]));
	int _min = min(a[0], min(a[1], a[2]));

	if (_max == a[1]) return true;
	if (_min == a[1]) return true;
	return false;
}

vi d(7);
int dfs(int depth)
{
	if (depth == 7)
	{
		bool ok = true;
		rep(i, 0, 5)
		{
			if (!check({ d[i], d[i + 1],d[i + 2] })) ok = false;
		}
		if (ok)
			return 1;
		else
			return 0;
	}

	int ret = 0;
	rep(i, depth, 7)
	{
		swap(d[depth], d[i]);
		ret += dfs(depth + 1);
		swap(d[depth], d[i]);
	}

	return ret;
}

int main()
{
	rep(i, 0, 7) cin >> d[i];

	int ans = dfs(0);
	if (ans)
		cout << "YES" << endl;
	else
		cout << "NO" << endl;
}