MWC '15 #3 P2: Mechanical Pencils
View as PDF has recently become obsessed with mechanical pencils. He has  
 mechanical pencils (numbered 
 to 
) and 
 
 packs of graphite lead (numbered 
 to 
).
As you may know, a whole piece of lead can never be used up completely. It can be used up to a certain length, until the mechanical pencil loses grip of the lead, at which point the lead then must be discarded. The maximum length at which the lead may not be used by the mechanical pencil is  
 and may vary from pencil to pencil.
 purchased his lead packs from very questionable sources. As a result, there may be different amounts of lead  (
) and the lead may have different lengths 
 
.
Now wants to know which pencil and lead pack pair permits the maximum writing time. Total usable lead positively correlates with writing time, meaning the more usable lead he has, the longer he can write for.
Input Specification
The first line contains two space separated integers  and 
, the number of mechanical pencils and the number of lead packs respectively.
The next  lines contain integers 
, the 
 value of pencil 
.
The next  lines initiate with integer 
 denoting the number of lead this pack has, followed by 
 integers denoting the size, 
, of the 
 piece of lead.
Output Specification
Two space separated integers, the pencil and lead pack pair that permits the maximum writing time.
If two pencils are tied, then take the one theoretically better pencil, meaning the one that would allow more lead use on average if used on all possible sets of lead packs. If still tied, take the first one (the one with the lower index). If two lead packs are tied, then take the one with fewer pieces of lead. If they have the same amount of lead, take the first one.
Sample Input
2 2
2
4
4 1 2 2 1
1 4
Sample Output
1 2
Explanation of Sample Output
It is optimal to use pencil 1 with lead pack 2 for a maximum lead use of 2. All other combinations permit 0 lead use.
Comments
Since the original data were weak, an additional test case worth 10 marks was added, and all submissions were rejudged. Data were provided by grammer.
Can we have a proper input/output specification, with an explanation, because currently it leaves a lot up to question.
The output should be
2 2