import sys
for _ in[0]*int(input()):
 n,m,a,b,c,d=map(int,sys.stdin.readline().split());s=r=0
 while(r:=max(r,s,s+a*~-n+b*(y:=(c*~-n+d)//m)))*0>y*a*b:d=m+~d;s+=(a+b)*(a<0)+d//c*a;n,m,a,b,c,d=y,c,b+m//c*a,a,m%c,d%c
 print(r)