1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<string>
 5 #include<algorithm>
 6 #include<cmath>
 7 #define INF 0x3f3f3f3f
 8 using namespace std;
 9 const int maxn=1e4+10;
10 int dp[maxn];
11 int weight[505];
12 int money[505];
13 int main()
14 {
15     int T;
16     scanf("%d",&T);
17     while(T--)
18     {
19     //    memset(dp,0,sizeof(dp));
20         int E,F;
21         scanf("%d%d",&E,&F);
22         int v=F-E;
23         for(int i=0;i<=v;i++)
24         {
25             dp[i]=INF;
26         }
27         dp[0]=0;
28         int n;
29         scanf("%d",&n);
30         for(int i=1;i<=n;i++)
31         {
32             scanf("%d%d",&money[i],&weight[i]);
33         }
34         for(int i=1;i<=n;i++)
35         {
36             for(int k=weight[i];k<=v;k++)
37             {
38                 dp[k]=min(dp[k],dp[k-weight[i]]+money[i]);
39             }
40         }
41         if(dp[v]<INF)
42         {
43             printf("The minimum amount of money in the piggy-bank is %d.\n",dp[v]);
44         }
45         else
46         {
47             printf("This is impossible.\n");
48         }
49         
50     }
51     return 0;    
52 }