program filip;
var s,s1,s2,s3,s4,d,d1,d2,d3,d4:integer;
begin
readln(s);
readln(d);
s1:= s mod 10;
s2:= s div 10;
s3:= s2 mod 10;
s4:= s2 div 10;
d1:= d mod 10;
d2:= d div 10;
d3:= d2 mod 10;
d4:= d2 div 10;
if s1>d1 then write(s1,s3,s4)
else
write(d1,d3,d4);
end.