ec热身赛B

#include <bits/stdc++.h>
/*
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
*/
using namespace std;

const double eps = 1e-10;
const double pi = 3.1415926535897932384626433832795;
const double eln = 2.718281828459045235360287471352;

#define f(i, a, b) for (int i = a; i <= b; i++)
#define scan(x) scanf("%d", &x)
#define mp make_pair
#define pb push_back
#define lowbit(x) (x&(-x))

#define fi first
#define se second
#define SZ(x) int((x).size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define summ(a) (accumulate(all(a), 0ll))

typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;

using ll=long long;

ll tt,x,y,z,k,s; 
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>tt;
    f(S,1,tt){
        cin>>x>>y>>z>>k>>s;
        if(x+y*s<k){
            cout<<x+y*s<<"\n";
        }else if(x-z*s>=k){
            cout<<x-z*s<<"\n";
        }
        else {
            ll mi=k-z,ma=k-1+y,l=0,r=s;
            while(l<r){
                ll mid=(l+r)>>1,tmp=x+mid*y-(s-mid)*z;
                if(tmp>ma){
                    r=mid;
                }else if(tmp<mi){
                    l=mid;
                }else break;
            }
            ll mid=(l+r)>>1,tmp=x+mid*y-(s-mid)*z;
            cout<<tmp<<"\n";
        }
    }
    return 0;
}