move must be performed if there exists a line that goes through the new organizes of, another directions of b and (0,0). If not, the move can't be performed and the focuses stay at their unique directions (xa,ya) and (xb,yb), individually. The numeration of focuses doesn't change after certain
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the move must be performed if there exists a line that goes through the new organizes of, another directions of b and (0,0).
If not, the move can't be performed and the focuses stay at their unique directions (xa,ya) and (xb,yb), individually.
The numeration of focuses doesn't change after certain focuses are eliminated. When the focuses are eliminated, they can't be picked in any later moves. Note that you need to move the two focuses during the move, you can't leave them at their unique directions.
What is the most extreme number of moves you can perform? What are these moves?
In case there are various replies, you can print any of them.
Input
The primary line contains a solitary integer n (1≤n≤2⋅105) — the number of focuses.
The I-th of the following n lines contains four integers
Output
In the primary line print a solitary integer c — the most extreme number of moves you can perform.
Every one of the following c lines ought to contain a portrayal of a move: two integers an and b (1≤a,b≤n, a≠b) — the focuses that are eliminated during the current move. There ought to be a way of moving focuses an and b as per the assertion so that there's a line that goes through the new arranges of a, the new organizes of b and (0,0). No eliminated point can be picked in a later move.
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