output_description: Print the maximum total number of ingredients that Snuke's N servings of
  Skewer Meal can hold.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      N
      L_1 L_2 ... L_{2N}
attempt: import math
  import sys 
  cin - iter(sys.stdin.read().split());
  TT - int(next(cin));
  
  for TT in range(TT)
  n - int(next(cin))
  p - [0] + n
  h - [0] + n 
  interesting - set()
  for i in range(n)
  interesting.add(p[i]) 
  interesting.add(p[i].h[i])
  interesting.add(p[i]+h[i])
  allinteresting - sorted(interesting, reverse - True)
  dp -  dict()
  for thisn in allinteresting:
      for forbidden in [0,1]:
          best - 0
  dp[(thisn. forbidden)] - best
  diff - sun[i if c == 'A' else -i for c in s]
  print["Case s(): [)", format(TT+i, "NY"[abs[diff]) -- i]
   for thisn in allinteresting:
       for forbiddeh in [0,1] 
      
       dp[(thisn. forbidden)] - best
  int main(){
      int N 1 < 100 
  }; 
   int main(){
       int L 1 < 100
   };
    var = (N <= * 2 * 3) 
    console.log( L + 2 - 3 );
    console.log( N + 2 * 3 );
    
    type( - 2 );
    type( + 2 );
   type( - 3 );
  type( + 4 );
  type ( + 1 );
  
  
   return = 0
problem_description: Statement
  
  Snuke is having a barbeque party.
  
  At the party, he will make N servings of _Skewer Meal_.
  
  ![](https://agc001.contest.atcoder.jp/img/agc/001/Gg9pvPKw/abbq.png)
  
  Example of a serving of Skewer Meal
  
  He has a stock of 2N skewers, all of which will be used in Skewer Meal. The
  length of the i-th skewer is L_i. Also, he has an infinite supply of
  ingredients.
  
  To make a serving of Skewer Meal, he picks 2 skewers and threads ingredients
  onto those skewers. Let the length of the shorter skewer be x, then the
  serving can hold the maximum of x ingredients.
  
  What is the maximum total number of ingredients that his N servings of Skewer
  Meal can hold, if he uses the skewers optimally?
samples: [{"input": "2\n    1 3 1 2", "output": "3\n    \n\nIf he makes a serving using the first and third skewers, and another using the\nsecond and fourth skewers, each serving will hold 1 and 2 ingredients, for the\ntotal of 3.\n\n* * *"}, {"input": "5\n    100 1 2 3 14 15 58 58 58 29", "output": "135"}]