#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;

typedef long double db;

const int N = 207;
const int INF = 1e9;

void bad(){
	cout << "impossible" << "\n";
	//exit(0);
}

db g[N][N];


int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	map<string, int> id;
	
	FOR(i, 0, N){
		FOR(j, 0, N){
			g[i][j] = INF;
		}
		g[i][i] = 0;
	}
	
	int n, q;
	cin >> n >> q;
	int sz = 0;
	
	vector<pair<PII, db>> edges;
	
	FOR(i, 0, n){
		string s, t;
		double val;
		cin >> s >> s >> t >> val >> t;
		
		if(!id.count(s))
			id[s] = sz++;
		int v = id[s];
		
		if(!id.count(t))
			id[t] = sz++;
		int to = id[t];
		val = log(val);
		
		edges.PB(MP(MP(v, to), val));
		edges.PB(MP(MP(to, v), -val));
	}
	FOR(it, 0, sz){
		FOR(from, 0, sz){
			for(auto e : edges){
				int v = e.F.F;
				int to = e.F.S;
				db w = e.S;
				
				g[from][to] = min(g[from][to], g[from][v] + w);
			}
		}
	}
	cout << fixed << setprecision(9);
	while(q--){
		double val;
		string s, t;
		cin >> val >> s >> t >> t;
		
		int v = id[s];
		int to = id[t];
		if(g[v][to] > 1e8){
			bad();
			continue;
		}
		cout << val * exp(g[v][to]) << "\n";		
	}
	

	
	
	
	return 0;
}