PIGBANK  PiggyBank
Before ACM can do anything, a budget must be prepared and the necessary financial support obtained. The main income for this action comes from Irreversibly Bound Money (IBM). The idea behind is simple. Whenever some ACM member has any small money, he takes all the coins and throws them into a piggybank. You know that this process is irreversible, the coins cannot be removed without breaking the pig. After a sufficiently long time, there should be enough cash in the piggybank to pay everything that needs to be paid.
But there is a big problem with piggybanks. It is not possible to determine how much money is inside. So we might break the pig into pieces only to find out that there is not enough money. Clearly, we want to avoid this unpleasant situation. The only possibility is to weigh the piggybank and try to guess how many coins are inside. Assume that we are able to determine the weight of the pig exactly and that we know the weights of all coins of a given currency. Then there is some minimum amount of money in the piggybank that we can guarantee. Your task is to find out this worst case and determine the minimum amount of cash inside the piggybank. We need your help. No more prematurely broken pigs!
Input
The input consists of T test cases. The number of them (T) is given on the first line of the input file. Each test case begins with a line containing two integers E and F. They indicate the weight of an empty pig and of the pig filled with coins. Both weights are given in grams. No pig will weigh more than 10 kg, that means 1 <= E <= F <= 10000. On the second line of each test case, there is an integer number N (1 <= N <= 500) that gives the number of various coins used in the given currency. Following this are exactly N lines, each specifying one coin type. These lines contain two integers each, Pand W (1 <= P <= 50000, 1 <= W <=10000). P is the value of the coin in monetary units, W is it's weight in grams.
Output
Print exactly one line of output for each test case. The line must contain
the sentence
"The minimum amount of money in the piggybank is X.
"
where X is
the minimum amount of money that can be achieved using coins with
the given total weight. If the weight cannot be reached exactly,
print a line "This is impossible.
".
Example
Sample Input: 3 10 110 2 1 1 30 50 10 110 2 1 1 50 30 1 6 2 10 3 20 4 Sample output: The minimum amount of money in the piggybank is 60. The minimum amount of money in the piggybank is 100. This is impossible.
hide comments
pimp_69:
20190509 08:06:43
In the second test case, it shows that min amount of money is 100 but the min amount of money is 120. With 1 coin of value(50) and 70 coins of value(1). Please look at the second test case or if there is some other method you guys are using to calculate the minimum amount then please let me know. Thank U.. 

dkkv0000:
20190211 15:35:07
1) watch tusharoy dp 01 knapsack


harry_shit:
20190119 07:55:57
now i know what kind of happiness it is, to get ac in 1 go!! 

bloodgreed99:
20181224 14:33:45
[f] there was also a [f]ing full stop after the answer it costed me 1 whole day


snor_lax13:
20181126 06:54:41
Use unbounded knapsack for this. 

itssanat:
20181104 09:38:35
ac in one go :) !!! 

joe85123:
20181017 10:23:06
puts("This is impossible.") gave WA, cout << "This is impossible.\n"; gave AC.


shivansh55:
20181004 20:05:26
Pay heed to period and format of answer...costed me 1WA... 

Autorun:
20180929 17:35:32
@admin increase the time limit for python solutions, please! 

avik26091998:
20180807 23:02:23
Bottom up is so clinical ..Got TLE with top down.. 
Added by:  adrian 
Date:  20040606 
Time limit:  5s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  ACM Central European Programming Contest, Prague 1999 