translator note Russias widespread grade system grade 5 4 3 2 high well roughly correspond a b c F respectively american grade systemthe term come end student start think grade Today professor tell student grade course given automatically calculate simple average arithmetic mean grade give lab work term round near integer the round favour student 45 round 5 example 3 44 round 4this bode Vasya do not think lab work influence receive grade bad 5 maybe dread 2 however professor allow redo work Vasyas choose increase average grade Vasya want redo lab work possible order 5 course of course Vasya 5 lab work choose redohelp Vasya calculate minimum lab work Vasya redo