var
a:string;
b:array[1..100]of string;
i,max,k:integer;
begin
readln(a);
a:=' '+a;
for i:=1 to length(a)do
if (a[i]=' ')and(a[i-1]<>' ')then inc(k)else
if a[i]<>' 'then b[k]:=b[k]+a[i];
max:=0;
for i:=1 to k do
if length(b[i])>max then max:=length(b[i]);
for i:=1 to k do
if length(b[i])=max then writeln(b[i]);
readln;
end.