#include <cstdio>

 #include <cstring>

 #include <cstdlib>

 int main() {

     int t;

     int T, b;

     int i;

 #ifndef ONLINE_JUDGE

     freopen("data.in", "r", stdin);

 #endif

     scanf("%d", &t);

     while (t--) {

         scanf("%d %d", &T, &b);

         if ( % b) {

             printf("Impossible!\n");

         } else {

             if (T == ) {

                 for (i=; i>; --i) {

                     if (i%b == )

                         break;

                 }

                 if (i == ) {

                     printf("Impossible!\n");

                 } else {

                     printf("%d\n", i);

                 }

             } else {

                 for (i=; i>; --i) {

                     if (i%b == )

                         break;

                 }

                 while (T-- >= ) {

                     printf("");

                 }

                 printf("%d\n", i);

             }

         }

     }

     return ;

 }