使用 std::map 枚举所有木棍并去重即可。

#include <bits/stdc++.h>
#define int long long
using namespace std;
signed main()
{
    map <int, int> p;
    int a, b;
    cin >> a >> b;
    p[0] = 1;
    p[a] = 1;
    p[a + a] = 1;
    p[b] = 1;
    p[a + b] = 1;
    p[a + a + b] = 1;
    p[b + b] = 1;
    p[a + b + b] = 1;
    p[a + a + b + b] = 1;
    cout << p.size() << endl;
    return 0;
}