#include<bits/stdc++.h>
#define pb emplace_back
using namespace std;
using ll = long long;
const int maxn = 10;
void done() {
    cout << "done" << endl;
    exit(0);
}
int mv[maxn];
vector<vector<int>> ask(vector<int> a) {
    cout << "next ";
    for (int i : a) cout << i << ' ', ++mv[i];
    cout << endl;
    int k;
    cin >> k;
    vector<vector<int>> res(k);
    for (int i = 0;i < k;++i) {
        string tmp;
        cin >> tmp;
        for (auto j : tmp) res[i].pb(j-'0');
    }
    return res;
}
// [, )
vector<int> range(int l, int r) {
    vector<int> res(r-l);
    iota(res.begin(), res.end(), l);
    return res;
}
int x;
void get_x() {
    auto advance = [&](int b) {
        while (mv[b] != 1<<b) {
            auto vv = ask(range(b, 10));
            if (vv.size() != b+1) {
                for (auto vec : vv) if (vec.size() != 1)
                    return *min_element(vec.begin(), vec.end());
            }
        }
        return -1;
    };
    for (int i = 0;i < 10;++i) {
        int v = advance(i);
        if (~v) {
            x = mv[i] - mv[v];
            break;
        }
    }
}
signed main(){
    ios_base::sync_with_stdio(0), cin.tie(0);
    ask(range(0, 10));
    get_x();

}