var
a,b: string;
i: byte;
begin
readln(a);
for i := 1 to length(a) do
begin
if a[i] <> ' ' then b := b + a[i];
if (a[i] = ' ') or (i = length(a)) then
begin
if b <>'' then
if b[1] = b[length(b)] then
writeln(b);
b := ''
end;
end;
readln
end.