怪异钟

一个钟只有分针（仅能表示0~59分），它自己不会走，只有投入一种硬币，它才会走。硬币上标有一个数字d，则该钟向前走当前时间s（分钟）的d倍，例如当时钟分针为45分钟时(s=45)，投入d=2的硬币，该钟将向前走45*2=90分钟，指向15分。现在输入时钟的当前分钟，和硬币上的数字d，问最少投入多少个这样的硬币后指针指向0点，如果永远不可能指向0点，则输出impossible。

-Weird clock a clock the minute hand only (can only be expressed from 0 to 59 points), which he will not go, and only put a coin, it will go. Coins a number d, the clock to move forward the current time s (min) d times, for example, when the clock minute hand is 45 minutes (s = 45), investment in d = 2 coins, the clock will move forward 45* 2 = 90 minutes walk, point to 15 points. The number d in the current minute of the input clock and coins, ask for at least put into the number of coins after the pointer to point to 0:00, if you never point to 0:00, then the output impossible.