program Project2;

{$APPTYPE CONSOLE}

var n,a,b,r:integer;
v,s:real;
f1,f2:text;
begin
assign(f1,'input.txt');
reset(f1);
while not(eof(f1)) do begin
readln(f1,n,a,b,r);
v:=(a/2.54*300)*(b/2.54*300)*3/8/1024;
end;
close(f1);
assign(f2,'output.txt');
rewrite(f2);
writeln(f2,v:6:2);
close(f2);
end.