#include<bits/stdc++.h>

#define ll long long
#define ld long double
#define pb push_back

using namespace std;

int l,s,t;
int solve(int v1, int v2, int knock){
    if(v2-v1<=t)return knock;
    int slt=(knock+1)*s;
    int vl=(v1+v2)/2,vr=v2-t;
    vl=min(vl,vr);
    ll pos=(ll)vr*slt;
    if(pos>l)return -1;
    int ans=-1;
    while(vl<=vr){
        int vm=(vl+vr)>>1;
        ll pos=(ll)vm*slt;
        int r=solve(vm,v2,knock+1);
        bool ok=1;
        if(r!=-1){
            int l=solve(v1,vm,knock+1);
            if(l==-1){
                r=-1;
            }
            else{
                r=max(r,l);
            }
        }
        if(r==-1){
            vl=vm+1;
        }
        else{
            ans=r;
            vr=vm-1;
        }
    }
    return ans;
}


int main(){
    int o;
    scanf("%i",&o);
    while(o--){
        int v1,v2;
        scanf("%i %i %i %i %i",&l,&v1,&v2,&t,&s);
        int x=solve(v1,v2,0);
        if(x==-1){
            printf("impossible\n");
        }
        else{
            printf("%i\n",x);
        }
    }
}