#include <stdio.h>

char truck[2010][8];
int truckDiff[2010];
int vyskyt[30];

void Clear() {
  for(int i = 0; i < 30; i++)
    vyskyt[i] = 0;
}

void ClearTruck() {
  for(int i = 0; i < 2010; i++)
    truckDiff[i] = 0;
}

int main() {
  int n = 0;
  scanf("%d", &n);
  while(n != 0) {
    for(int i = 0; i < n; i++)
      scanf("%s\n", truck[i]);
    ClearTruck();
    for(int i = 0; i < 7; i++) {
      Clear();
      for(int j = 0; j < n; j++) {
        vyskyt[truck[j][i] - 'a']++;
      }
//      for(int j = 0; j < 2; j++)
//        printf("%d ", vyskyt[j]);
//      printf("\n");
      int maxIndex = 0;
      int max = 0;
      char maxLetter = 'a';
      for(int k = 0; k < 30; k++) {
        if (vyskyt[k] > max) {
          maxLetter = k + 'a';
          maxIndex = k;
          max = vyskyt[k];
	}
      }
      int diff = 0;
      for(int k = 0; k < 30; k++) {
        if (k == maxIndex) continue;
	if (vyskyt[k] != 0) diff += vyskyt[k];
      }
      for(int k = 0; k < n; k++)
        if (truck[k][i] == maxLetter) truckDiff[k] += diff;
    }
    int min = 0, minIndex;
    for(int i = 0; i < n; i++) {
      if (truckDiff[i] > min) { min = truckDiff[i]; minIndex = i; }
    }
//    printf("T %d\n", minIndex);
    int count = 0;
    for(int i = 0; i < n; i++) {
      if (minIndex == i) continue;
      for(int j = 0; j < 7; j++)
        if (truck[minIndex][j] != truck[i][j]) count++;
    }
    printf("The highest possible quality is 1/%d.\n", count);
    scanf("%d", &n);
  }
  return 0;
}