import static java.lang.Math.*;
import java.io.*;
import java.util.*;

public class mortgage {

	void solve() throws Exception {
		
		int X = nextInt();
		int Y = nextInt();
		int N = nextInt();
		double r = nextDouble();
		while(X!=0 && Y!=0){

			double c = 1.0+(r/1200.0);
			int d = 12*N;
			
			double ls = ((double)X) * pow(c,d);
			double ps = ((double)Y) * ((pow(c,d)-1)/(c-1));
			
//			debug(c,d,ls,ps);
			
			if((ps-ls)>1e-9){
				println("YES");
			} else {
				println("NO");
			}
			
			X = nextInt();
			Y = nextInt();
			N = nextInt();
			r = nextDouble();			
		}
		
	}
	
	
	
	////////////////////////////////////////////////////////////////

	BufferedInputStream bis = new BufferedInputStream(System.in);
	
	String nextWord() throws IOException {
		StringBuilder sb = new StringBuilder();
		int ch = bis.read();
		while (ch<=' ') ch=bis.read();
		while (ch>' ') {
			sb.append((char)ch);
			ch=bis.read();
		}
		return new String(sb);
	}
	String nextLine() throws IOException {
		StringBuilder sb = new StringBuilder();
		int ch = bis.read();
		while (ch<=' ') ch=bis.read();
		while (ch!='\n' && ch!='\r') {
			sb.append((char)ch);
			ch=bis.read();
		}
		return new String(sb);
	}
	int nextInt() throws NumberFormatException, IOException {
		return Integer.parseInt(nextWord());
	}
	long nextLong() throws NumberFormatException, IOException {
		return Long.parseLong(nextWord());
	}
	double nextDouble() throws NumberFormatException, IOException {
		return Double.parseDouble(nextWord());
	}
	
	void print(Object...o) {
		if (o==null) return;
		if (o.length==0) return;
		System.out.print(o[0]);
		for (int i=1; i<o.length; ++i) System.out.print(" "+o[i]);
	}
	void println(Object...o) {
		print(o);
		System.out.println();
	}
	
	String str(Object o) {
		return o.toString();
	}
	void debug(Object...o) {
		System.err.println(Arrays.deepToString(o));
	}
	
	public static void main(String[] args) throws Exception {
		new mortgage().solve();
	}

}