#include <bits/stdc++.h>
using namespace std;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define FOR(i, begin, end) for(int i=(begin);i<(end);i++)
#define REP(i, n) FOR(i,0,n)
#define IFOR(i, begin, end) for(int i=(end)-1;i>=(begin);i--)
#define IREP(i, n) IFOR(i,0,n)
#define Sort(v) sort(v.begin(), v.end())
#define Reverse(v) reverse(v.begin(), v.end())
#define all(v) v.begin(),v.end()
#define SZ(v) ((int)v.size())
#define Lower_bound(v, x) distance(v.begin(), lower_bound(v.begin(), v.end(), x))
#define Upper_bound(v, x) distance(v.begin(), upper_bound(v.begin(), v.end(), x))
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define bit(n) (1LL<<(n))
#define debug(x) cout << #x << "=" << x << endl;
#define vdebug(v) { cout << #v << "=" << endl; REP(i_debug, v.size()){ cout << v[i_debug] << ","; } cout << endl; }
#define mdebug(m) { cout << #m << "=" << endl; REP(i_debug, m.size()){ REP(j_debug, m[i_debug].size()){ cout << m[i_debug][j_debug] << ","; } cout << endl;} }
#define pb push_back
#define fi first
#define se second
#define int long long
#define INF 1000000000000000000
template<typename T> istream &operator>>(istream &is, vector<T> &v){ for (auto &x : v) is >> x; return is; }
template<typename T> ostream &operator<<(ostream &os, vector<T> &v){ for(int i = 0; i < v.size(); i++) { cout << v[i]; if(i != v.size() - 1) cout << endl; }; return os; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, pair<T1, T2> p){ cout << '(' << p.first << ',' << p.second << ')'; return os; }
template<typename T> void Out(T x) { cout << x << endl; }
template<typename T1, typename T2> void chOut(bool f, T1 y, T2 n) { if(f) Out(y); else Out(n); }

using vec = vector<int>;
using mat = vector<vec>;
using Pii = pair<int, int>;
using v_bool = vector<bool>;
using v_Pii = vector<Pii>;

//int dx[4] = {1,0,-1,0};
//int dy[4] = {0,1,0,-1};
//char d[4] = {'D','R','U','L'};

const int mod = 1000000007;
//const int mod = 998244353;

struct edge{int to, cost, id;};

class Graph
{
public:
    int N;
    vector<vector<edge>> G;

    Graph(int N): N(N){
        G = vector<vector<edge>>(N, vector<edge>(0));
    }

    void add_Directed_edge(int from, int to, int cost = 1, int id = 0){
        G[from].push_back(edge({to, cost, id}));
    }

    void add_Undirected_edge(int v1, int v2, int cost = 1, int id = 0){
        add_Directed_edge(v1, v2, cost, id);
        add_Directed_edge(v2, v1, cost, id);
    }

};

signed main(){

    const int M = 1000000000;
    vec d;
    for(int i = 1; i * i <= M; i++) if(M % i == 0){
        d.pb(i);
        if(i * i < M) d.pb(M / i);
    }
    Sort(d);
    
    int n = SZ(d);
    Graph G(n);
    REP(i, n){
        if(M % (d[i] * 2) == 0){
            int j = Lower_bound(d, d[i] * 2);
            G.add_Undirected_edge(i, j, 1);
        }
        if(M % (d[i] * 5) == 0){
            int j = Lower_bound(d, d[i] * 5);
            G.add_Undirected_edge(i, j, 1);
        }
        if(d[i] * 5 > M) G.add_Directed_edge(i, n - 1, 1);
    }
    
    mat dp(n, vec(n, INF));
    REP(i, n){
        dp[i][i] = 0;
        for(auto e: G.G[i]) dp[i][e.to] = 1;
    }

    FOR(t, 2, 36){
        REP(i, n) REP(j, n) if(dp[i][j] == INF){
            bool ok = false;
            for(auto ei: G.G[i]){
                bool ng = false;
                for(auto ej: G.G[j]) if(dp[ei.to][ej.to] >= t) ng = true;
                if(!ng) ok = true;
            }
            if(ok) dp[i][j] = t;
        }
    }

    int x1, x2; cin >> x1 >> x2;
    int v1 = Lower_bound(d, x1), v2 = Lower_bound(d, x2);
    REP(_, 35){
        if(dp[v1][v2] == 0) return 0;
        else if(dp[v1][v2] == 1){
            cout << x2 << endl;
            return 0;
        }else{
            int v0 = -1;
            for(auto ei: G.G[v1]){
                bool ng = false;
                for(auto ej: G.G[v2]) if(dp[ei.to][ej.to] >= dp[v1][v2]) ng = true;
                if(!ng){
                    v0 = ei.to;
                    break;
                }
            }
            assert(v0 != -1);
            v1 = v0;
            x1 = d[v1];
            cout << x1 << endl;
            cin >> x2;
            v2 = Lower_bound(d, x2);
        }
    }

    return 0;
}