read t
for ((i=0;i<t;i++)); do
  read n m
  if ((n/4 <= m/2)); then
    echo $((n/4*3))
  else
    r=$((n-m/2*4))
    echo $((m/2*3+r/10*6+(r%10>=6 ? 3 : 0)))
  fi
done