program echo;
var
  tmp,a,b:string;
  ans,ans1,ans2,i:integer;
begin
  assign (input,'echo.in');
  reset (input);
  readln (a);
  readln (b);
  if length(a)>length(b) then begin
    tmp:=a;
    a:=b;
    b:=tmp;
  end;
  close (input);
  for i:=length(a) downto 1 do
  if copy(a,length(a)-i+1,i)=copy(b,1,i) then begin
    ans1:=i;
    break;
  end;
  for i:=length(a) downto 1 do
  if copy(a,1,i)=copy(b,length(b)-i+1,i) then begin
    ans2:=i;
    break;
  end;
  assign (output,'echo.out');
  rewrite (output);
  if ans1>ans2 then ans:=ans1 else ans:=ans2;
  writeln (ans);
  close (output);
end.