program SPIRAL;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var i,N,M,P,N1,M1 :integer;
 v,vh:text;
begin
  { TODO -oUser -cConsole Main : Insert code here }
 assign (vh,'SPIRAL.dat');
 assign (v, 'SPIRAL.sol');
 reset (vh);
 read (vh,n,m);
 close (vh);
 i:=1;
 rewrite (v);
 if (N=1) then write (v,'0') else
 if (M=1) then write (v,'1') else
 if N=2 then write (v,'2') else
 if M=2 then write (v,'3') else
 begin
 inc (N); inc (M);
 while (M<>M1+1) and (N<>N1+1) do
 begin
 if i=1 then begin inc (N1); inc (i); inc(p); end else
 if i=2 then begin m:=m-1; inc (i); inc(p); end else
 if i=3 then begin n:=n-1; inc (i); inc(p); end else
 if i=4 then begin inc (M1); i:=1; inc(p); end;
 end;
 p:=p-1;
 write (v,p);
 end;
 close (v);
end.