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

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

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



void solve()
{
	int l, v1, v2, t, s;
	cin >> l >> v1 >> v2 >> t >> s;
	
	int inpV2 = v2;
	
	l /= s;
		
	int cnt = 0;
	int inter = 1;
	
	set<PII> used;
	while(v2 - v1 > t * inter)
	{
		//if(cnt > 100)
		//{
		//	cout << "impossible\n";
		//	return;
		//}
		int v = l / (cnt + 1);
		if(v + t < v2)
		{
			int nprom = (v2 - v - 1) / t;
			if(inter <= nprom)
			{
				cout << "impossible\n";
				return;
			}
			//cout << l << " " << v1 << " " << inpV2 << " " << t << " " << s << " " << v2 << " " << inter << " " << nprom << "\n";
		
			v2 -= t * nprom;
			inter = 2 * (inter - nprom);
		}
		else
			inter = 2 * inter;
		cnt++;
	}
	cout << cnt << "\n";
}


int main()
{
	ios::sync_with_stdio(0); 
	cin.tie(0);
	
	int t;
	cin >> t;
	while(t--)
		solve();
	
	return 0;
}