program jxfg(input,output);

type
  re=record
    x:boolean;
    key:longint; 
  end;

var
  m,n,i,a,xx,yy,ans:longint;
  st:array[1..20002]of re;

procedure qsort(l,h:longint);
  var
    i,j,m:longint;
    t:re;
  begin
    i:=l;
    j:=h;
    m:=st[(i+j) div 2].key;

   repeat
     while st[i].key>m do
       inc(i);

     while m>st[j].key do
       dec(j);

     if i<=j then
     begin
       t:=st[i];
       st[i]:=st[j];
       st[j]:=t;
       inc(i);
       dec(j);
     end;
   until i>j;

   if i<h then
     qsort(i,h);

   if j>l then
     qsort(l,j);
  end;

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

  readln(n,m);
  for i:=1 to n-1 do
  begin
    readln(a);
    st[i].key:=a;
    st[i].x:=true;
  end;

  for i:=n to n+m-2 do
  begin
    readln(a);
    st[i].key:=a;
  end;

  qsort(1,n+m-2);

  xx:=1;
  yy:=1;
  for i:=1 to n+m-2 do
    if st[i].x then
    begin
      inc(xx);
      ans:=ans+st[i].key*yy
    end
    else
    begin
      inc(yy);
      ans:=ans+st[i].key*xx
    end;

  writeln(ans);
  close(input);
  close(output);
end.