LOTT - Xổ số
Tác giả: ladpro98
Ngôn ngữ: Pascal
var a, b, m, n: int64;
c: double;
inp: text;
s: string;
begin
assign(inp,'');reset(inp);
while not eof(inp) do begin
readln(inp,s);
if s = '[END]' then break;
readln(inp,n);readln(inp);
m := 5 * n - 5;
a := 120 * (m * (m-1) + m) + 24;
b := (m+1) * (m+2) * (m+3) * (m+4);
c := a / b;
writeln(c:0:11);
end;
end.