program Tong;
var
n: integer;
i: integer;
sum: real;
begin
write('Nhap so nguyen duong n (chia het cho 5): ');
readln(n);
sum := 0;
for i := 1 to n do
begin
if i mod 5 = 1 then
sum := sum + 1/i;
end;
writeln('Tong A la: ', sum);
readln;
end.