var a,b,c,d:string;
begin
//In thuong
a:='Dong thu nhat';
b:='Dong thu hai';
c:='Dong thu ba';
d:='Dong thu tu';
//Xuoi
writeln(a);
writeln(b);
writeln(c);
writeln(d);
//Nguoc
for i:=length(a) downto 1 do write(a[i]);
writeln;
for i:=length(b) downto 1 do write(b[i]);
writeln;
for i:=length(c) downto 1 do write(c[i]);
writeln;
for i:=length(d) downto 1 do write(d[i]);
writeln;
//In hoa
a:=upcase(a);
b:=upcase(b);
c:=upcase(c);
d:=upcase(d);
//Xuoi
writeln(a);
writeln(b);
writeln(c);
writeln(d);
//Nguoc
for i:=length(a) downto 1 do write(a[i]);
writeln;
for i:=length(b) downto 1 do write(b[i]);
writeln;
for i:=length(c) downto 1 do write(c[i]);
writeln;
for i:=length(d) downto 1 do write(d[i]);
writeln;
readln
end.
