#include <stdio.h>

 #include <string.h>

 #define MAXLEN 105

 #define MAXNUM 105

 char buf[MAXNUM][MAXLEN];

 char src1[MAXLEN], src2[MAXLEN];

 int case_n, n;

 int f(int index, int len) {

     int max = ;

     int i=, j, k;

     char *p;

     while (i+max < len) {

         for (j=; j<=max; ++j)

             src1[j] = src2[max-j] = buf[index][i+j];

         src1[max+] = src2[max+] = '\0';

         k = ;

         for (j=; j<n; ++j) {

             p = strstr(buf[j], src1);

             if (p == NULL)

                 p = strstr(buf[j], src2);

             if (p == NULL) {

                 k = ;

                 break;

             }

         }

         if (k)

             ++max;

         else

             ++i;

     }

     return max;

 }

 int main() {

     int i, j, tmp, len;

     scanf("%d", &case_n);

     while (case_n--) {

         scanf("%d", &n);

         tmp = MAXLEN;

         for (i=; i<n; ++i) {

             scanf("%*c%s", buf[i]);

             len = strlen(buf[i]);

             if (len < tmp) {

                 tmp = len;

                 j = i;

             }

         }

         tmp = f(j, tmp);

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

     }

     return ;

 }