#include <iostream>
using namespace std;
  
int main() {
    float c, s, a1, a2, a3;
    cin >> c >> s >> a1 >> a2 >> a3;
     
    float travelTime = c / s;
    float problemTime = a1 + a2 + a3;
    float totalTime = travelTime + problemTime;
     
    if (totalTime <= 20) {
        cout << "YES"; 
    } else {
        cout << "NO";
    }
     
    return 0;
}
/**************************************************************
	Problem: 1634
	User: linzihang
	Language: C++
	Result: Accepted
	Time:5 ms
	Memory:2072 kb
****************************************************************/