Bob competitive programmer he want red need strict training regime he go annual meeting grandmaster ask n effort need reach redOh I spend x_i hour solve problem say ith Bob want train math skill answer write number minutes 60 cdot x_i thank grandmaster go home Bob write number lead zeroes example grandmaster answer spend 2 hour Bob write 000120 instead 120alice want tease Bob take number Bob write follow independently rearrange digit write random number this way Alice generate n number denote y_1 y_nfor number help Bob determine y_i permutation number divisible 60 possibly lead zero