#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
#define min(a,b) a<b?a:b
#define INF 0x7ffffff
#define N 10010

int n,s;
int dp[N];
int v[N],w[N]; //算了，统一一下，n代表种类，s代表总容量，v代表价值，w代表重量

int main()
{
    int T,i,j;
    scanf("%d",&T);
    while(T--)
    {
        int s1,s2;
        scanf("%d%d%d",&s1,&s2,&n);
        s=s2-s1;
        for(i=1;i<=n;i++)
        {
            scanf("%d%d",&v[i],&w[i]);
        }
        for(i=1;i<=N;i++)
        {
            dp[i]=INF;
        }
        dp[0]=0;
        for(i=1;i<=n;i++)
        {
            for(j=w[i];j<=s;j++)
            {
                dp[j]=min(dp[j],dp[j-w[i]]+v[i]);
            }
        }
        if(dp[s]!=INF)
            cout<<"The minimum amount of money in the piggy-bank is "<<dp[s]<<‘.‘<<endl;
        else
            cout<<"This is impossible.\n";
    }
    return 0;
}