#include <cstdlib>
#include <cstdio>

bool solve() {
		int X,Y,N;
		double r;
				
		scanf("%d %d %d %lf", &X, &Y, &N, &r);
		if (X == 0) return false;

		double d = X;
		double add = r/1200;

		for (int i = 0; i < N; i++) {
			for (int mon = 0; mon < 12; mon++) {
				//printf("Debt %lf, plus %lf, pay %lf, new %lf\n", d, d*add, (double)Y, d+d*add-Y);
				d += d*add;
				d -= Y;
				//printf("End of mon %d year %d; %lf\n", mon, i, d);
			}
			if (d <= 0) {
				printf("YES\n");
				return true;
			}
		}
		printf("NO\n");
		return true;
}

int main (int, char**) {
	
	while (solve());
	//solve();
	return EXIT_SUCCESS;
}