import java.util.*; import java.io.*; import java.text.*; publicclass ACM_2066{ publicstaticvoid main(String rgs[]) throws Exception { BufferedReader stdin = new BufferedReader( new InputStreamReader(System.in)); String s =null; while((s = stdin.readLine())!=null) { StringTokenizer st =new StringTokenizer(s); int x = Integer.parseInt(st.nextToken()); int y = Integer.parseInt(st.nextToken()); int z = Integer.parseInt(st.nextToken()); double r = Math.sqrt((double)(x*x+y*y+z*z)); double pi =3.1415926535897932384626433832795; DecimalFormat f =new DecimalFormat("#.000"); System.out.println(f.format(4*pi*r*r*r/3.0)); } } }