How to Win Coding Competitions: Secrets of Champions

Hello guys, I tried resolve this problem: Good kg of Flauta Bread, using binary search but I not had luck, please if somebody know how to resolve this problem, help me, please, thanks in regards link in online judge — Caribbean Online Judge: http://coj.uci.cu/24h/problem.xhtml?pid=3382

Anyone know how to hack codes in the real contest, I've tried but nothing, please somebody that help me, greetings carlos

For all coders, The Caribbean Training Contest #34 will celebrated 2 october(tuesday) to 8:45 am ( Cuban timezone ), with a duration of 4 hours, the format of competition is as the ACM, this contest is a training for the national contest the Cuba, if you want participate, you should login in the COJ and ready, i hope a good partipation the Codeforces coders, bye

Pay Attention, the results of the Caribbean Local Contests of the ACM-ICPC is ready, Congratulations to the winners of each university. This is my first official contest and my team( all novice ) arranged for the Caribbean National Contests of the ACM-ICPC(CUB) with date for 13-10-2012 in the Matanzas University, the teams presented a good preparation, for see more clicked here and if you like to select the contest and participate in a virtual contest clicked here, bye krlos_Aut92...

Click here to see the teams that will particpate in this contest. The Contest will begin 29th Saturday( Havana timezone ), the results of this contest be published in this site, Good Luck for all participants, greetings