1    none
      3       3
      4    none
     11      11
    642       3
    128      11
    886    none
      2       2
 999983  999983
 999985      13
 999987    none
 999989      53
 999991    none
 999993       3
 999995       5
 999997       7
 999999    none
     72    none
     73      73
     74      11
   1013    1013
   1014    none
   1015       7
 500008      13
 500009  500009
 500010    none
    101     101
   1001       2
  10001       2
 100001       2
   9731       2
   1091    1091
   9101      11