Thanks for the participation!
1649A - Game was authored by Jeffrey and prepared by DmitryGrigorev
1649B - Game of Ball Passing was authored by low_ and prepared by low_ and DmitryGrigorev
1648A - Weird Sum was authored and prepared by cookiedoth
1648B - Integral Array was authored by grphil and prepared by shishyando
1648C - Tyler and Strings was authored and prepared by Tikhon228
1648D - Serious Business was authored and prepared by ligaydima
1648E - Air Reform was authored and prepared by grphil
1648F - Two Avenues was authored by I_love_myself and prepared by isaf27