#include <iostream>

 #include <cstdio>

 using namespace std;

 const int MAXN = , INF = 0x3f3f3f3f;

 int n, ts, tf, s[MAXN], f[MAXN], d[MAXN], dp[MAXN][MAXN];

 int cal(int now, int i)

 {

     if (s[i] >= now) return s[i] + d[i];

     return now + (f[i] - (now - s[i]) % f[i]) % f[i] + d[i];

 }

 int main()

 {

     int T;

     cin >> T;

     for (int t = ; t <= T; t++)

     {

         cin >> n >> ts >> tf;

         for (int i = ; i <= n - ; i++)

         {

             cin >> s[i] >> f[i] >> d[i];

         }

         dp[][] = ;

         for (int i = ; i <= n - ; i++)

             for (int j = i + ; j <= n - ; j++)

                 dp[i][j] = INF;

         for (int i = ; i <= n - ; i++)

         {

             dp[i][] = cal(dp[i - ][], i);

             for (int j = ; j <= i; j++)

                 dp[i][j] = min(cal(dp[i - ][j], i), cal(dp[i - ][j - ] + ts, i));

         }

         cout << "Case #" << t << ": ";

         bool flg = false;

         for (int i = n - ; i >= ; i--)

         {

             if (dp[n - ][i] <= tf)

             {

                 flg = true;

                 cout << i << endl;

                 break;

             }

         }

         if (!flg) puts("IMPOSSIBLE");

     }

     return ;

 }