import math
t=int(input())
def calc(a,b,c,x,y,d,t):
res=a*t
d-=x*t
if d<=0:
return res
mi=min(d,y)
d-=mi
res+=b*mi
res+=d*c
return res
def calc2(a,b,c,x,y,d,t):
res=(a+b*y)*t
d-=(x+y)*t
if d<=0:
return res
mi=min(d,x)
d-=mi
res+=a
mi=min(d,y)
d-=mi
res+=mi*b
res+=d*c;
return res
for o in range(0,t):
a,b,c,x,y,d=map(int,input().split())
ans=calc(a,b,c,x,y,d,1)
for sb in range(1,5)
ans=min(ans,calc(a,b,c,x,y,d,sb))
ans=min(ans,calc(a,b,c,x,y,d,sb-1))
if (d+x-1)//x+1>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x+1))
if (d+x-1)//x>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x))
if (d+x-1)//x-1>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x-1))
if (d+x-1)//x-2>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x-2))
if (d+x-1)//x-3>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x-3))
if (d+x-1-y)//x>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x))
if (d+x-1-y)//x+1>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x+1))
if (d+x-1-y)//x-1>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x-1))
if (d+x-1-y)//x-2>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x-2))
if (d+x-1-y)//x-3>0:
ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x-3))
if (d+x+y-1)//(x+y)+1>=0:
ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)+1))
if (d+x+y-1)//(x+y)>=0:
ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)))
if (d+x+y-1)//(x+y)-1>=0:
ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)-1))
if (d+x+y-1)//(x+y)-2>=0:
ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)-2))
if (d+x+y-1)//(x+y)-3>=0:
ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)-3))
g=(d+x+y-1)//(x+y)
if x*g<=d:
ans=min(ans,g*a+(d-x*g)*b)
print(ans)