#include <iostream>
#include <sstream>
#include <math.h>
#include <stack>
#include <set>
#include <algorithm>
#include <string>
#include <queue>
#include <stack>
#include <map>
#include <cstdio>
#include <vector>
using namespace std;

#define INF (1 << 30)
#define INFLL (1LL << 60)

int main() {
	int a,b,c;
	cin >> a >> b >> c;

	int how;
	if(a % b == 0) how = a / b;
	else how = a / b + 1;
	c = c * (how * 2 / 3);
	if(c >= a) cout << "YES" << endl;
	else cout << "NO" << endl;
	return 0;
}