var
a, b, c, d, n : integer;
begin
readln(n);
a := n div 1000;
b := n div 100 mod 10;
c := n div 10 mod 10;
d := n mod 10;
writeln(d * 1000 + c * 100 + b * 10 + a);
end.
输入：5340
输出：435