#include <cmath>
#include <iomanip>
#include <ios>
#include <iostream>
#include <map>
#include <vector>

using namespace std;

map<string, vector<pair<string, long double>>> g;
map<string, long double> dist;

void dfs(string curr, long double d) {
  dist[curr] = d;

  for (auto [u, x] : g[curr]) {
    if (dist.find(u) == dist.end()) {
      dfs(u, d + log(x));
    }
  }
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  int n, q;
  cin >> n >> q;

  for (int i = 0; i < n; i++) {
    long double a, tmp1;
    string u, v, tmp2;
    cin >> tmp1 >> u >> tmp2 >> a >> v;

    g[u].push_back({v, a});
    g[v].push_back({u, 1 / a});
  }

  for (int i = 0; i < q; i++) {
    long double a;
    string u, tmp, v;
    cin >> a >> u >> tmp >> v;

    dist.clear();
    dfs(u, log(a));

    if (dist.find(v) != dist.end()) {
      cout.precision(15);
      cout << scientific << exp(dist[v]) << endl;
    } else
      cout << "impossible" << endl;
  }
}