/* Sun Jul  4 09:40:34 JST 2004 */
/* Sun Jul  4 10:44:09 JST 2004 */
#include <stdio.h>
#include <string.h>
#include <limits.h>

int N, M;
char street[256][17]; int N_street;
int adjacent[256][256];

int lookup(char s[])
{
  int i;
  for (i = 0; i < N_street; i++) {
    if (strcmp(street[i], s) == 0) { return i; }
  }
  return -1;
}

int register_street(char s[])
{
  int found;
  if ((found = lookup(s)) < 0) {
    strcpy(street[N_street], s);
    N_street++;
    return N_street-1;
  }
  return found;
}

void FloydWarshall()
{
  int k, i, j;
  for (k = 0; k < N_street; k++) {
    for (i = 0; i < N_street; i++) {
      for (j = 0; j < N_street; j++) {
        if (adjacent[i][j] > adjacent[i][k] + adjacent[k][j]) {
          adjacent[i][j] = adjacent[i][k] + adjacent[k][j];
        }
      }
    }
  }
}

int samelevel(int street1, int street2)
{
  int i, cond1 = 0;
  if (street1 == street2) { return 0; }
  for (i = 0; i < N_street; i++) {
    if ((adjacent[street1][i] == 1 && adjacent[street2][i] == 1) ||
        (adjacent[i][street1] == 1 && adjacent[i][street2] == 1)) {
      cond1 = 1;
    }
    if ((adjacent[street1][i] == 1 && adjacent[i][street2] == 1) ||
        (adjacent[i][street1] == 1 && adjacent[street2][i] == 1)) {
      return 0;
    }
  }
  return cond1;
}

int main()
{
  int i, j, street1, street2;
  char s[64], s1[32], s2[32];
  while (1) {
    gets(s); N = atoi(s); if (N == 0) { break; }
    for (i = 0; i < 256; i++) {
      for (j = 0; j < 256; j++) {
        adjacent[i][j] = INT_MAX / 2;
      }
    }
    N_street = 0;
    for (i = 0; i < N; i++) {
      gets(s);
      strcpy(s1, strtok(s,    "-"));
      street1 = register_street(s1);
      strcpy(s2, strtok(NULL, "-"));
      street2 = register_street(s2);
      adjacent[street1][street2] = 1;
    }
    printf("%d\n", N_street);

    for (i = 0; i < N_street; i++) {
      for (j = 0; j < N_street; j++) {
        if (samelevel(i, j)) { adjacent[i][j] = adjacent[j][i] = 0; }
      }
    }
    FloydWarshall();

    gets(s); M = atoi(s);
    for (i = 0; i < M; i++) {
      gets(s);
      strcpy(s1, strtok(s,    "-"));
      street1 = lookup(s1);
      strcpy(s2, strtok(NULL, "-"));
      street2 = lookup(s2);
      if (street1 >= 0 && street2 >= 0 &&
          (adjacent[street1][street2] < INT_MAX / 2 &&
           adjacent[street1][street2] % 2 == 1)) {
        printf("YES\n");
      }
      else {
        printf("NO\n");
      }
    }
  }
  return 0;
}