var s1,s2,st,max:string;
i,j,n:byte;
f1,f2:text;
begin
// clrscr;
assign(f1,'Bai2.inp');reset(f1);
assign(f2,'Bai2.out');rewrite(f2);
readln(f1,s1);readln(f1,s2);
n:=length(s1);
for i:=1 to n do
begin
st:='';
for j:=i to n do
begin
st:=st+s1[j];
if pos(st,s2)=0 then
begin
delete(st,length(st),1);
break;
end;
end;
if length(st)>length(max) then max:=st;
end;
write(f2,max);
close(f1);close(f2);
end.