#include <iomanip>
#include <iostream>
#include <unordered_map>
#include <queue>

#define ld long double

using namespace std;

int main() {
    int n, q;
    cin >> n >> q;
    cout << setprecision(20);

    unordered_map<string, unordered_map<string, ld>> units;
    string a, b, _;
    ld x;
    for (int i = 0; i < n; i++) {
        //     1   unit  =  value unit
        cin >> _ >> a >> _ >> x >> b;
        units[a][b] = x;
        units[b][a] = 1 / x;
    }

    for (int i = 0; i < q; i++) {
        //   value unit  to  unit
        cin >> x >> a >> _ >> b;

        unordered_map<string, ld> seen = {{a, x}};
        queue<string> todo({a});
        while (!todo.empty()) {
            string curr = todo.front();
            if (curr == b) {
                cout << seen[b] << endl;
                break;
            }
            todo.pop();
            for (auto const& [k, v] : units[curr]) {
                if (seen.find(k) == seen.end()) {
                    seen[k] = seen[curr] * v;
                    todo.push(k);
                }
            }
        }
        if (todo.empty()) cout << "impossible" << endl;
    }
}