Computer Programming Contest Preparation

    1 2
    2 
    3 7
    4 -45 -62
    5     30 13
    6     -7 -24
    7     61 44
    8     -83 -100
    9     13 -4
   10     100 83
   11 
   12     7
   13     -45 -62
   14     30 13
   15     -7 -24
   16     60 44
   17     -83 -100
   18     13 -4
   19     100 83
   20 
   21