var
x,nx,ny,y,i,n: longint;
c: char;
e,k,l: integer;
s,s2,s3,s4: string;
begin
read(y, x);
if (x=1) or (y=1) then begin n:=0; writeln(n);end else begin
 if x>=y then begin ny:=y-1; nx:=ny+1; end;
 if x<y then begin nx:=x; ny:=nx; end;
 if (nx<1000000000) and (ny<1000000000) then begin n:=nx+ny-1;writeln
(n); end else
                    begin
                    str(nx,s);
                    str(ny,s2);
                    if length(s)>=length(s2) then x:=length(s) else
x:=length(s2);
                     for i:=1 to x do
                      begin
                      nx:=0;
                      ny:=0;
                      if length(s)-i>=0 then
                          val(s[length(s)-i+1],nx,e);
                      if length(s2)-i>=0 then
                          val(s2[length(s2)-i+1],ny,e);
                          nx:=nx+ny;
                      if i=1 then begin nx:=nx-1; if nx=-1 then
begin nx:=9; l:=1; end; if nx>9 then
                      begin k:=1; nx:=nx-10; str(nx,s3) end else
                      begin k:=0; str(nx,s3); end; end else begin
nx:=nx+k-l; l:=0;if nx=-1 then begin l:=1; nx:=9; end;
                       if nx>9 then begin k:=1; nx:=nx-10 end else
k:=0; str(nx,s3); end;
                      s4:=s3+s4;
                      end;writeln(s4);end;end;
end.