#include <iostream>
#include <algorithm>

using namespace std;

int lowbit(int x)
{
    return x & -x; // ① x & (~x + 1) -> 得到的最后一位-x = ~x + 1 
}

int main()
{
    int x = 8;
    cout << lowbit(x) << endl;
    return 0;
}