Codeforces Global Round 6 A. Competitive Programmer According to the problem statement you are given some digits ( 0 - 9 ) , is it possible to make a number using all digits which is divisible by 60 ? To make a number from the digits which is divisible by 60, we need a zero and more than one even digits and digits sum must be divisible by 3. Code : B. Dice Tower According to the the picture given in the problem the sum of any two oppsite side of the dice is 7. Accept top dice , sum of all visible side pips in a dice is 21 - 7 = 14. We can make a tower , which all visible pips is equal to n , if n = 14 * d + 14 + pip n = 14 * D + pip where pip = { 1, 2, 3, 4, 5, 6 } Code :