void update (int v, int tl, int tr, int l, int r, int add) {
	if (l > r)
		return;
	if (l == tl && tr == r)
		t[v] += add;
	else {
		int tm = (tl + tr) / 2;
		update (v*2, tl, tm, l, min(r,tm), add);
		update (v*2+1, tm+1, tr, max(l,tm+1), r, add);
	}
}