#include<bits/stdc++.h>
using namespace std;

int quick(int a,int b)
{
    int s = 1;
    while (b > 0) {
        if (b & 1) {//b=b>>1保证了在最后一步肯定会执行该if判断
            s = s * a;		
           }
        a = a * a;
        cout<<"b="<<b<<endl;
		cout<<"s="<<s<<endl;
		cout<<endl;
        b = b >> 1;
	}
    return s;
}

int main() {
	printf("%d",quick(2,10));
	return 0;
}