program test4;
var
i:integer;
a:array[1..10]of char;
procedure try(t:integer);
begin
if t=10 then write(a[t])
else
begin
try(t+1);write(a[t]);
end;
end;
begin
for i:=1 to 10 do read(a[i]);
try(1);
end.
输入：123459876a
输出：a678954321