{双亲数
 数值递推
 Author: yangbohua
 Time: 2011-04-12}

program parents;
var
  f:array[0..1000000] of int64;
  i,j,x,d:longint;
  a,b,c,last,i1:int64;

begin
  assign(input,'parents.in');
  reset(input);
  assign(output,'parents.out');
  rewrite(output);

  readln(a,b,x);
  last:=-1;
  if a<b then c:=a else c:=b;
  i:=(c div x)*x;
  while i>=x do
  begin
    i1:=i;
    f[i]:=(a div i1)*(b div i1);
    if f[i]=last then
      f[i]:=f[i+x]
    else
    begin
      last:=f[i];
      d:=c div i;
      for j:=2 to d do
        f[i]:=f[i]-f[i*j];
    end;
    i:=i-x;
  end;

  writeln(f[x]);
  close(input);
  close(output);
end.