#include <bits/stdc++.h>
using namespace std;

#define SZ(a) (int)a.size()
#define ALL(a) a.begin(), a.end()
#define FOR(i, a, b) for (int i = (a); i<(b); ++i)
#define RFOR(i, b, a) for (int i = (b)-1; i>=(a); --i)
#define MP make_pair
#define PB push_back
#define F first
#define S second
#define FILL(a, b) memset(a, b, sizeof(a))

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;

const int INF = 1e9 + 7;

const int N = 447;

map<string, int> m;
vector<pair<int, long double>> g[N];

long double val[N];
bool used[N];

void dfs(int v, long double a)
{
	used[v] = 1;
	val[v] = a;
	for (auto& [to, d] : g[v])
		if (!used[to])
			dfs(to, a * d);
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	
	int idx = 0;
	int n, q;
	cin >> n >> q;
	FOR (i, 0, n)
	{
		string s, t;
		long double d;
		cin >> s >> s >> t >> d >> t;
		if (!m.count(s))
			m[s] = idx++;
		if (!m.count(t))
			m[t] = idx++;
		g[m[s]].PB({m[t], d});
		g[m[t]].PB({m[s], 1 / d});
	}
	cout << fixed << setprecision(25);
	FOR (i, 0, q)
	{
		long double x;
		string s, t;
		cin >> x >> s >> t >> t;
		int v = m[s];
		dfs(v, x);
		if (val[m[t]] < -1)
			cout << "impossible\n";
		else
			cout << val[m[t]] << '\n';
		FOR (j, 0, SZ(m))
		{
			used[j] = 0;
			val[j] = -2;
		}
	}
	
	
	return 0;
}