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

int main(void)
{
    char *a, *aux, *p, *s;
    int c, n = 0, len, k = 0;

    a = (char *) malloc(1);

    if (!a)
    {
        printf("Nu pot aloca memorie.\n");
        exit(EXIT_FAILURE);
    }

    a[0] = 0;

    while ((c = getchar()) != EOF)
    {
        aux = (char *) realloc(a, n + 2);

        if (!aux)
        {
            free(a);
            printf("Nu pot redimensiona blocul.\n");
            exit(EXIT_FAILURE);
        }
        else
            a = aux;

        a[n] = c;
        a[n + 1] = 0;

        n ++;
    }

    s = (char *) malloc(1);

    if (!s)
    {
        printf("Nu pot aloca memorie.\n");
        free(a);
        exit(EXIT_FAILURE);
    }

    s[0] = 0;
    p = strtok(a, "\t\n ");

    while (p != NULL)
    {
        if (k)
        {
            len = strlen(s);

            if (tolower(s[len - 2]) == tolower(p[0]) && tolower(s[len - 1]) == tolower(p[1]))
            {
                aux = (char *) realloc(s, len + strlen(p) + 2);

                if (!aux)
                {
                    free(a);
                    free(s);

                    printf("Nu pot redimensiona blocul.\n");
                    exit(EXIT_FAILURE);
                }
                else
                    s = aux;

                strcat(s, "-");
                strcat(s, p);
            }
        }
        else
        {
            aux = (char *) realloc(s, strlen(p) + 2);

            if (!aux)
            {
                free(a);
                free(s);

                printf("Nu pot redimensiona blocul.\n");
                exit(EXIT_FAILURE);
            }
            else
                s = aux;

            strcat(s, p);
        }

        p = strtok(NULL, "\t\n ");
        k ++;
    }

    printf("%s", s);

    free(s);
    free(a);
    return 0;
}