program mn;
uses crt;
var ff,fg:text;
f,i,k:integer;
z1,z2:string;
BEGIN
ClrScr;
Assign(ff,'f.txt');
Assign(fg,'g.txt');
reset(ff);
reset(fg);
While not eof(ff) do
begin
readln(ff,z1);readln(fg,z2);inc(f,length(z1));
if (z1<>z2)and(k<>1)
then begin
k:=1;
for i:=1 to length(z1) do
if z1[i]<>z2[i]
then begin
inc(f,length(z1));
i:=length(z1);
end;
writeln(f);
end;

end;
if k<>1
then writeln('sovpadajut');
readln;
END.