public class Prog54H {
	public static void main(String[] args){
		double islandDiameter = 4.16;
		double islandRadius = islandDiameter / 2;
		double Pi = 3.14159;
		double islandArea = islandRadius * islandRadius * Pi;
		double lakeRadius = 0.95;
		double lakeArea = lakeRadius * lakeRadius * Pi;
		double amtLand = islandArea - lakeArea;
		amtLand = (int)(amtLand * 1000 + 0.5)/1000.000;
		System.out.println("An island with a 4.16 mile diameter and 0.95 mile radius lake has "+ amtLand + " square miles of cultivatable land");
	}
}