Your task is to create a Funnel data structure. It consists of three basic methods: fill(), drip() and toString()/to_s/__str__. Its maximum capacity is 15 data.

Data should be arranged in an inverted triangle, like this:

 \1 2 3 4 5/
  \7 8 9 0/
   \4 5 6/
    \2 3/
     \1/

The string method should return a multi-line string to display current funnel data arrangement:

 var funnel = new Funnel()
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \   /
      \ /

The method fill() should accept one or more arguments to fill in the funnel:

 var funnel = new Funnel()
 funnel.fill(1)
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \   /
      \1/
 funnel.fill(2)
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \2  /
      \1/
 funnel.fill(3)
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \2 3/
      \1/
 funnel.fill(4,5)
 console.log(funnel.toString())
  \         /
   \       /
    \4 5  /
     \2 3/
      \1/
 funnel.fill(6,7,8,9)
 console.log(funnel.toString())
  \         /
   \7 8 9  /
    \4 5 6/
     \2 3/
      \1/

In each row, fill() always fill data from left to right.

The method drip() should drip the bottom value out of funnel and returns this value:

 (continue the example above)
 var v = funnel.drip()
 console.log(v)
 1
 console.log(funnel.toString())
  \         /
   \  8 9  /
    \7 5 6/
     \4 3/
      \2/

As you can see, the bottom 1 was dripping out. The number above it will fill it's place. The rules to fill are: Select one of the two numbers above it, which bear the "weight" of relatively large. In other words, there are more numbers on this number. Is this a bit hard to understand? Please see the following:

 In the example above, before the execution of drip(), funnel is:
  \         /
   \7 8 9  /
    \4 5 6/
     \2 3/
      \1/

• After drip(), 1 will be dripped out.
• We should choose a number between 2 and 3 to fill the place of 1.
• 2 has 5 numbers on it(4,5,7,8,9). 3 has 4 numbers on it(5,6,8,9)
• So we choose 2 to fill the place of 1
• And now, the place of 2 is empty.
• We also need choose a number between 4 and 5 to fill the place of 2.
• 4 has 2 numbers on it(7,8). 5 has 2 numbers on it too(8,9)
• There are same "weight" on 4 and 5,
• In this case, we choose the number on the left
• So we choose 4 to fill the place of 2
• And then choose 7 to fill the place of 4

Let us continue to drip():

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \    9  /
    \7 8 6/
     \5 3/
      \4/

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \       /
    \7 9 6/
     \8 3/
      \5/

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \       /
    \  9 6/
     \7 3/
      \8/

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \       /
    \    6/
     \7 9/
      \3/

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \7 6/
      \9/

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \  6/
      \7/

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \   /
      \6/

 funnel.drip()
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \   /
      \ /

When the funnel is empty, drip() will return null/nil/None

 var v= funnel.drip()
 console.log(v)
 null
 console.log(funnel.toString())
  \         /
   \       /
    \     /
     \   /
      \ /

Another edge case is: When funnel is full, fill() will not change the funnel.

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