你可能熟悉二项式系数 $\binom{m}{k}$，其定义为 $\binom{m}{k} = \frac{m!}{k!(m-k)!}$，其中 $m$ 和 $k$ 是非负整数且 $k \le m$。令 $T_2(n)$ 为满足 $0 \le k \le m < n$ 的奇数二项式系数的个数。你在本次比赛中将学到的最有用的数学不等式是 $$0.812556n^{\log_2 3} \le T_2(n) \le n^{\log_2 3}$$ Emma 不喜欢这种不精确的不等式，她想精确地计算出 $T_2(n)$。你能帮帮她吗？
输入包含一行，为一个整数 $n$，$1 \le n \le 10^{11}$。
输出一行，为 $T_2(n)$ 的值。
4
9
6
15
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