#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
#define rep(i, n) for(ll i = 0; i < (ll)(n); ++i)
#define rep1(i, n) for(ll i = 1; i <= (ll)(n); ++i)
#define rrep(i, n) for(ll i = (ll)(n) - 1; i >= 0; --i)
#define rrep1(i, n) for(ll i = (ll)(n); i >= 1; --i)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#ifdef DEBUG
#define dbg if(true)
#else
#define dbg if(false)
#endif
template<typename T> bool chmin(T &a, const T &b) {if(a>b) {a=b; return true;} return false;}
template<typename T> bool chmax(T &a, const T &b) {if(a<b) {a=b; return true;} return false;}
template <typename T> void print(const T &a) {cout << a << '\n';}
template <typename T> void print(const vector<T> &v1) {for(int i=0; i<v1.size(); ++i){if(i) {cout << ' ';} cout << v1[i];} cout << '\n';}
template <typename T> void print(const vector<vector<T>> &v2) {for(int i=0; i<v2.size(); ++i) print(v2[i]); cout << '\n';}

template<typename T>
struct pair_hash {
  size_t operator()(const pair<long long, long long>& p) const {
    size_t h1 = hash<long long>{}(p.first);
    size_t h2 = hash<long long>{}(p.second);
    return h1 ^ (h2 + 0x9e3779b9 + (h1 << 6) + (h1 >> 2));
  }
};


void solve() {
  auto f = [&] (ll i, ll x) -> ll {
    ll res = -1;
    if(i == 0) if(x >= 2 && x % 2 == 0) res = x / 2;
    if(i == 1) if(x >= 5 && x % 5 == 0) res = x / 5;
    if (i == 2) res = min(2 * x, 1000000000LL);
    if (i == 3) res = min(5 * x, 1000000000LL);
    if(x == res) return -1;
    if(1000000000LL % res != 0) return -1;
    return res;
  };
  unordered_map<pair<ll, ll>, ll, pair_hash<ll>> mp;
  rep(koma2, 10) rep(koma5, 10) rep(kiri2, 10) rep(kiri5, 10) {
    ll komaval = 1; rep(i, koma2) komaval *= 2; rep(i, koma5) komaval *= 5;
    ll kirival = 1; rep(i, kiri2) kirival *= 2; rep(i, kiri5) kirival *= 5;
    if(komaval == kirival) mp[{komaval, kirival}] = 0;
    else if(abs(koma2 - kiri2) + abs(koma5 - kiri5) == 1) mp[{komaval, kirival}] = 1;
    else mp[{komaval, kirival}] = 1LL<<60;
  }

  rep(turn, 35) {
    for(const auto& [key, val] : mp) {
      const auto& [komaval, kirival] = key;
      ll best = 1LL<<60;
      rep(komai, 4) {
        if (f(komai, komaval) == -1) continue;
        ll kiriworst = 0;
        rep(kirii, 4) if(f(kirii, kirival) != -1) chmax(kiriworst, mp[{f(komai, komaval), f(kirii, kirival)}]);
        chmin(best, kiriworst);
      }
      chmin(mp.at({komaval, kirival}), best + 1);
    }
  }

  ll komaval, kirival; cin >> komaval >> kirival;
  while(true) {
    if(komaval == kirival) return;
    ll next = 0; ll bestcost = 1LL<<60;
    rep(i, 4) if(f(i, komaval) != -1) if(chmin(bestcost, mp[{f(i, komaval), kirival}])) next = f(i, komaval);
    cout << next << endl;
    komaval = next;
    if(komaval == kirival) return;
    cin >> kirival;
  }

  return;
}

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  int test_case = 1;
  // cin >> test_case;
  // cout << std::setprecision(15);
  while (test_case--) {
    solve();
  }
  return 0;
}