var
 x,y,z,w:string;
 i,j,l,max1,max2,l1,l2:integer;
begin
 assign(input,'echo.in');
 assign(output,'echo.out');
 reset(input);
 rewrite(output);
 readln(x);
 readln(y);
 l1:=length(x);
 l2:=length(y);
 max1:=-2;
 max2:=-2;
  for i:=1 to length(y+x) do
   begin
    z:=copy(x,length(x)+1-i,i);
    w:=copy(y,1,i);
    if (z=w)and(max1<i) then begin max1:=i;end;
   end;
  for i:=1 to length(y+x) do
   begin
    z:=copy(y,length(y)+1-i,i);
    w:=copy(x,1,i);
    if (z=w)and(max2<i) then begin max2:=i;end;
   end;
 if max1>max2 then write(max1) else write(max2);
 close(input);
 close(output);
end.