char * join(char ** woerter,int anzahl,char * str) {
    int letter_count=0;
    int sl=strlen(str);
    for (int i=0;i<anzahl;i++) {
        letter_count+=strlen(woerter[i]);
        if (i<anzahl-1)
            letter_count+=sl;
    }
    char pstr[letter_count+1];
    char * joined=pstr;
    for (int i=0;i<anzahl;i++) {
        char * wp=woerter[i];
        int wl=strlen(wp);
        for (int j=0;j<wl;j++) {
            *pstr=*wp;
            pstr++;
            wp++;
        }
        if (i<anzahl-1) {
            char * sp=str;
            for (int k=0;k<sl;k++) {
               
 *pstr=*sp;
               
 pstr++;
               
 sp++;
            }
        }
    }
    *pstr=0;
    return joined;
}