CF1174A Ehab Fails to Be Thanos
In fact, is to \ (\ sum \ limits_ {i = 1} ^ n a_i \) and \ (\ sum \ limits_ {n + 1} ^ {2n} a_i \) with the largest difference, like row about the order
CF1174B Ehab Is an Odd Person
Obviously a nature that if at least one odd and one even, can be adjusted, that is, ascending order
Otherwise it can not carry out any operation
CF1174C Ehab and a Special Coloring Problem
The pre-out every prime number, \ (X \ CDOT P_i \) fill \ (I \) like