for (int s = 0; l <= S; ++s)
	for (int l = 0; l <= L; ++l)
		f(p, s, l) = 1;

for (int s = 1; l <= S; ++s)
	for (int l = 1; l <= L; ++l) {
		if (l > 1)
			f(p, s, l) = p * f(p, s - 1, l) + (1 - p) * f(p, s, l - 1);
		else
			f(p, s, l) = p * f(p, s - 1, l);
	}