1 //一道纯粹的完全背包。
 2 #include <iostream>
 3 #include <cstdio>
 4 #include <cstring>
 5 #include <cmath>
 6 #include <algorithm>
 7 #include <vector>
 8 #include <queue>
 9 #include <stack>
10 #include <map>
11 #include <string>
12 #include <set>
13 #define ms(a,b) memset((a),(b),sizeof((a)))
14 using namespace std;
15 typedef long long LL;
16 const double EPS = 1e-8;
17 const int INF = 2e9;
18 const LL LNF = 2e18;
19 const int MAXN = 1e3+10;
20 
21 int wei[MAXN], val[MAXN], dp[10010];
22 
23 int main()
24 {
25     int T, n;
26     scanf("%d", &T);
27     while(T--)
28     {
29         int E, F, W;
30         scanf("%d%d", &E, &F);
31         W = F - E;
32 
33         scanf("%d", &n);
34         for(int i = 1; i<=n; i++)
35             scanf("%d%d", &val[i], &wei[i]);
36 
37         for(int i = 1; i<= W; i++)
38             dp[i] = INF;
39         dp[0] = 0;
40         for(int i = 1; i<=n; i++)
41         for(int j = 1; j<=W; j++)
42             if(j>=wei[i] && dp[j-wei[i]]!=INF )
43                 dp[j] = min(dp[j], dp[j-wei[i]]+val[i]);
44 
45         if(dp[W]!=INF)
46             printf("The minimum amount of money in the piggy-bank is %d.\n", dp[W]);
47         else
48             printf("This is impossible.\n");
49     }
50 }