#include <iostream>

typedef long long ll;
typedef double lf;

// #define DEBUG 1
struct IO
{
    #define MAXSIZE (1 << 20)
    #define isdigit(x) (x >= '0' && x <= '9')
    char buf[MAXSIZE], *p1, *p2;
    char pbuf[MAXSIZE], *pp;
    #if DEBUG
    #else
    IO() : p1(buf), p2(buf), pp(pbuf) {}
    ~IO() {fwrite(pbuf, 1, pp - pbuf, stdout);}
    #endif
    #define gc() (p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, MAXSIZE, stdin), p1 == p2) ? ' ' : *p1++)
    #define blank(x) (x == ' ' || x == '\n' || x == '\r' || x == '\t')

    template <typename T>
    void Read(T &x)
    {
        #if DEBUG
        std::cin >> x;
        #else
        bool sign = 0; char ch = gc(); x = 0;
        for (; !isdigit(ch); ch = gc())
            if (ch == '-') sign = 1;
        for (; isdigit(ch); ch = gc()) x = x * 10 + (ch ^ 48);
        if (sign) x = -x;
        #endif
    }
    void Read(char *s)
    {
        #if DEBUG
        std::cin >> s;
        #else
        char ch = gc();
        for (; blank(ch); ch = gc());
        for (; !blank(ch); ch = gc()) *s++ = ch;
        *s = 0;
        #endif
    }
    void Read(char &c) {for (c = gc(); blank(c); c = gc());}

    void Push(const char &c)
    {
        #if DEBUG
        putchar(c);
        #else
        if (pp - pbuf == MAXSIZE) fwrite(pbuf, 1, MAXSIZE, stdout), pp = pbuf;
        *pp++ = c;
        #endif
    }
    template <typename T>
    void Write(T x)
    {
        if (x < 0) x = -x, Push('-');
        static T sta[35];
        int top = 0;
        do sta[top++] = x % 10, x /= 10; while (x);
        while (top) Push(sta[--top] ^ 48);
    }
    template <typename T>
    void Write(T x, char lst) {Write(x), Push(lst);}
} IO;
#define Read(x) IO.Read(x)
#define Write(x, y) IO.Write(x, y)
#define Put(x) IO.Push(x)

using namespace std;

const int MAXN = 1e3 + 10;

int t;
lf cm, bnd[MAXN];

ll bg[MAXN], pw[MAXN];
inline bool Calc(int n, lf v1, lf v2)
{
    // cout << "Calc " << n << ' ' << v1 << ' ' << v2 << "\n";
    for (int i = 1; i <= n; i++) bnd[i] = cm / i, bg[i] = pw[i] = 0;
    while (n && bnd[n] < v1) n--;
    for (int i = n; i >= 1 && n - i <= 32; i--) bg[i] = (1ll << n - i), pw[i] = bg[i] << 1;
    // for (int i = 1; i <= n; i++) cout << bg[i] << ' ' << pw[i] << ' ' << bnd[i] << '\n';
    ll ad = 0, cur;
    while (n)
    {
        ll mn = 1e18; int p = 0;
        for (int i = n; i >= 1 && n - i <= 32; i--)
        {
            if ((bg[i] + ad) * t + v1 > bnd[i]) cur = 0;
            else cur = (ll)(((bnd[i] - v1) / t - bg[i] - ad) / pw[i]) + 1;
            if (mn > bg[i] + ad + cur * pw[i]) mn = bg[i] + ad + cur * pw[i], p = i;
        }
        if (n <= 32 && mn >= (1ll << n) + ad) return ((1ll << n) + ad) * t + v1 >= v2;
        if ((mn - 1) * t + v1 >= v2 - t) return 1;
        ll cnt = 0;
        if (bnd[p] > (mn - 1) * t + v1)
        {
            v1 = bnd[p] - mn * t;
            if (bnd[p] >= v2 - t) return 1;
        }
        else cnt--;
        // cout << mn << ' ' << p << " " << v1 << "\n";
        if (p == 1) break;
        for (int i = p; i <= n; i++)
            cnt += (mn - bg[i] - ad) / pw[i] + 1;
        mn -= ad, ad += cnt;
        for (int i = p - 1; i >= 1 && p - 1 - i <= 32; i--)
        {
            if (!bg[i]) { bg[i] = (1ll << p - 1 - i); continue; }
            ll c = mn + (pw[i + 1] >> 1);
            if (__builtin_ctzll(c) == n - i) bg[i] = c >> n - p + 1, mn = c;
            else bg[i] = (mn -= (pw[i + 1] >> 1)) >> n - p + 1;
        }
        n = p - 1;
        for (int i = n; i >= 1 && n - i <= 32; i--)
            pw[i] = 1ll << n - i + 1;
    }
    return 0;
}

inline void Solve(int v1, int v2)
{
    if (v2 - v1 <= t) return cout << "0\n", void();
    int l = 1, r = 200, mid;
    while (l <= r)
    {
        mid = l + r >> 1;
        if (Calc(mid, v1, v2)) r = mid - 1;
        else l = mid + 1;
    }
    if (l == 201) cout << "impossible\n";
    else cout << r + 1 << '\n';
    // cout << Calc(4, v1, v2) << "\n";
}

int main()
{
    // freopen("G.in", "r", stdin);
    // freopen("G.out", "w", stdout);
    #if DEBUG
    #else
    ios::sync_with_stdio(0), cin.tie(0);
    #endif
    int T;
    Read(T);
    while (T--)
    {
        int lb, rb, l, s;
        Read(l), Read(lb), Read(rb), Read(t), Read(s);
        cm = l / s;
        Solve(lb, rb);
    }
    return 0;
}