#include <stdio.h>
#include <stdlib.h>

char d[26000][17];
int dp[26000];
int z;
int n;

struct adj{
   int i;
   struct adj *next;
};

struct adj *a[26000];
int q[26000];
int dist[26000];

compar(int *a, int *b){
   int r;
   char at = d[*a][z];
   char bt = d[*b][z];
   if (at) d[*a][z] = '_';
   if (bt) d[*b][z] = '_';
   r = strcmp(d[*a],d[*b]);
   d[*a][z] = at;
   d[*b][z] = bt;
   return r;
}

main(){
   int i,j,k,m;
   for(n=0;;n++){
      gets(d[n]);
      if (!d[n][0]) break;
   }
   for (i=0;i<n;i++) dp[i] = i;
   for (z=0;z<16;z++){
      qsort(dp, n, sizeof(int), compar);
      for (i=0;i<n;i++){
         for (j=i+1;j<n;j++){
            if (!compar(&dp[i],&dp[j])) {
               struct adj *t = (struct adj *)malloc(sizeof(struct adj));
               t->i = dp[j];
               t->next = a[dp[i]];
               a[dp[i]] = t;
               t = (struct adj *)malloc(sizeof(struct adj));
               t->i = dp[i];
               t->next = a[dp[j]];
               a[dp[j]] = t;
            }else break;
         }
      }
   }

   for (m=0;;m++){
      int i1, i2;  char w1[20], w2[20]; int qn;
      if (2 != scanf(" %s %s",w1,w2)) break;
      if (m) printf("\n");
      for (i1=0;i1<n && strcmp(w1,d[i1]);i1++);
      for (i2=0;i2<n && strcmp(w2,d[i2]);i2++);
      for (i=0;i<n;i++) dist[i] = 999999;
      dist[i2] = 0;
      for (i=0;i<n;i++) q[i] = -1;
      q[0] = i2;
      qn = 1;
      for (i=0;i<qn && q[i] != i1;i++){
         struct adj *p;
         for (p=a[q[i]];p;p=p->next) {
            if (dist[p->i] == 999999) {
               dist[p->i] = dist[q[i]] + 1;
               q[qn++] = p->i;
            }
         }
      }
      if (i1 != n && i2 != n && dist[i1] != 999999) {
         int this = i1;
         printf("%s\n",w1);
         while (this != i2) {
            struct adj *p;
            for (p=a[this];p && dist[p->i] != dist[this]-1;p=p->next){}
            this = p->i;
            printf("%s\n",d[this]);
         }
      }else printf("No solution.\n");
   }
}