Given a fraction a/b, write it as a sum of different Egyptian fraction. For example, 2/3 = 1/2 + 1/6. There is one restriction though: there are k restricted integers that should not be used as a denominator. For example, if we can’t use 2..6, the best solution is: 2/3 = 1/7 + 1/9 + 1/10 + 1/12 + 1/14 + 1/15 + 1/18 + 1/28 The number of terms should be minimized, and then the large denominator should be minimized. If there are several solutions, the second largest denominator should be minimized etc. Input The first line contains the number of test cases T (T ≤ 100). Each test case begins with three integers a, b, k (2 ≤ a < b ≤ 876, 0 ≤ k ≤ 5, gcd(a,b) = 1). The next line contains k different positive integers not greater than 1000. Output For each test case, print the optimal solution, formatted as below. Extremely Important Notes It’s not difficult to see some inputs are harder than others. For example, these inputs are very hard input for every program I have: 596/829=1/2+1/5+1/54+1/4145+1/7461+1/22383 265/743=1/3+1/44+1/2972+1/4458+1/24519 181/797=1/7+1/12+1/2391+1/3188+1/5579 616/863=1/2+1/5+1/80+1/863+1/13808+1/17260 22/811=1/60+1/100+1/2433+1/20275 732/733=1/2+1/3+1/7+1/45+1/7330+1/20524+1/26388 However, I don’t want to give up this problem due to those hard inputs, so I’d like to restrict the input to “easier” inputs only. I know that it’s not a perfect problem, but it’s true that you can still have fun and learn something, isn’t it? Some tips:
2/2 Sample Output Case 1: 2/3=1/2+1/6 Case 2: 19/45=1/5+1/6+1/18 Case 3: 2/3=1/3+1/4+1/12 Case 4: 5/121=1/33+1/121+1/363 Case 5: 5/121=1/45+1/55+1/1089