可以在$C(64,3)={64\times 63 \times 62 \over 6}$的时间复杂度算出来

void solve(int deep, ll x, int sum) {
	if (sum >= 3) return;
	if (deep == 63) {
		ve.push_back(x);
		return;
	}
	rep(i, 0, 1) solve(deep + 1, (x << 1) | i, sum + i);
}