#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <cctype>
#include <string>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
using namespace std;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define FOR2(i,a,b) for (int i = (a); i > (b); ++i)
#define DEBUG(x) cout << '>' << #x << ':' << x << endl;
inline bool EQ(double a, double b) { return fabs(a-b) < 1e-9; }

const int INF = 1<<29;
typedef long long ll;
//////////////////////////////////////////////////////////////////////////////

int main()
{
	while (1)
	{
		double X,Y,N,r;
		scanf("%lf %lf %lf %lf", &X, &Y, &N, &r);
		if (X == 0 && Y == 0 && N == 0 && r == 0) break;
		if (r == 0) {
			if (X <= 12*N*Y) printf("YES\n");
			else printf("NO\n");
		} else {
			r /= 100.0;
			r /= 12.0;
			r += 1.0;
			double rr = pow(r, 12*N);
			double l = X*rr*(r-1);
			double p = Y*(rr-1);
			if (l <= p) printf("YES\n");
			else printf("NO\n");
		}
	}
	return 0;
}