#include<bits/stdc++.h>
#define int long long

using namespace std;

int sum[21][21];

signed main(){
    ios::sync_with_stdio(0); cin.tie(0);
//    freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);

    string role;

    cin >> role;

    if (role[0] == 'A') {
        int n;

        cin >> n;

        vector<int> a(n);

        int x = 0;

        for (int &u: a) {
            cin >> u;
            x ^= (1ll << u);
        }

        cout << x;
    }
    else {
        int x;

        cin >> x;
        vector<int> res;



        for (int i = 0 ; i < 20 ; i++) {
            if ((x >> i) & 1) {
                res.push_back(i);
            }
        }

        cout << res.size() << "\n";

        for (int &u: res) {
            cout << u << " ";
        }
    }
    return 0;
}