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Explan

• Susan likes to make a line drawing with ink. There‘re several dots on drawing paper.
• Your job is to tell Susan how to connect the dots so as to minimize the amount of ink used.
• If all the dots are connected, Susan will not draw anymore. In other words, the drawn figure does not need to be closed.

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Example

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Input

3		4		5
1 1		1 4		1 1
2 2		2 5		1 2
2 4		3 6		2 1
		1 1		2 2
        		5 5

• The first line is a Integer that indicating how many inputs to enter.
• From the next line, enter the x and y coordinates in one line.

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Output

3.41	5.83	7.24

• Your program must print a single real number to two decimal places: the minimum total length of ink lines that can connect all the dots.