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

#define MAX_CONNECTIONS 50
#define MAX_NODES       50

typedef struct node
{
    char        name[32];
    int         links;
    struct node *link[MAX_CONNECTIONS];
} Node;

static Node node[MAX_NODES] = {0};
static int nodes = 0;
static Node *start = NULL;
static Node *end = NULL;

static char *ReadLine(char *p, size_t size, FILE *fp)
{
    if ((p=fgets(p, size, fp)))
    {
        size_t l = strlen(p);

        while(l && p[l-1] == '\n')
        {
            p[--l] = 0;
        }
    }

    return p;
}

static Node *GetOrAddNode(const char *name)
{
    int f;

    for(f = 0; f < nodes; f++)
    {
        if (strcmp(name, node[f].name) == 0)
        {
            return node + f;
        }
    }

    if (f == MAX_NODES)
    {
        fprintf(stderr, "Too many nodes\n");
        exit(1);
    }

    strcpy(node[f].name, name);

    return node + f;
}

static void Link(Node *node1, Node *node2)
{
    node1->link[node1->links++] = node2;
    node2->link[node2->links++] = node1;
}

int main(void)
{
    char buff[4096];

    start = GetOrAddNode("start");
    end = GetOrAddNode("end");

    while(ReadLine(buff, sizeof buff, stdin))
    {
        Node *node1, *node2;
        char *p;

        p = strtok(buff, "-");
        node1 = GetOrAddNode(p);
        p = strtok(NULL, "-");
        node2 = GetOrAddNode(p);
        Link(node1, node2);
    }

    return 0;
}