丢失的牛

#include<iostream>
using namespace std;
int main()
{
    int n, m;
    cin >>n >>m;
    int res = 0;
    int num = 1, cnt = 1;
    for(int i = n;;)
    {
        if(cnt % 2 != 0 ||cnt == 1)
        {
            if(n < m && n + num >= m){
                res += m - i;
                break;
            }
            res += n + num - i;
            i = n + num;
        }
        else {
            if(n > m && n - num <= m){
                res += i - m;
                break;
            }
            res += i - n + num;
            i = n - num;
        }
        num *= 2;
        cnt ++;
    }
    cout << res <<endl;
}