char FirstChar (bool* end_of_file, bool* is_command, bool* incorrect_line){
    char x;
    x = getchar();
    if (!((x>='A' && x<='Z') || (x>='a' && x<='z')) && (x == '(' || (x>='0' && x<='9') || x == '-')) (*is_command) = false;
    else if ((x>='A' && x<='Z') || (x>='a' && x<='z')) (*is_command) = true;
    else (*incorrect_line) = true;
    return x;
}
void NextLine (bool* end_of_file, bool* is_command, StackNode** head){
    char x = 'a';
    int i = 1, key = 0;
    bool help = false, incorrect_line = false;
    char* array = (char*) malloc(sizeof(char)*MAX_COMMAND_CHARS);
    if (array == NULL) return;
    array[0] = (int)FirstChar(end_of_file, is_command, &incorrect_line);
    // na wszelki wypadek ustawiam zeby w ifach nie bylo cyrkow
    array[1] = 'H';
    while (x == '\n') x = getchar();
    while (x != '\n' && x != EOF && !help && !incorrect_line) {
        x = getchar();
        array[i] = x;
        ++i;
        if (array[0] == 'D' && array[1] == 'E' && array[2] == 'G' && array[3] == '_' && array[4] == 'B' && array[5] == 'Y'){
            help = true;
        }
        else if (array[0] == 'A' && array[1] == 'T'){
            help = true;
        }
    }
    if (help) scanf ("%d", &key);
    array[i-1] = '\0';
    if (incorrect_line) return;
    if ((*is_command)) InterpretingCommand(array, head, key);
    else if (CheckIfPolyIsCorrect(array)) {
        int index = 0;
        CheckLine(array, i-1);
        Poly new = NewPoly (array, &index);
        Push (head, new);
    }
    if (x == EOF) (*end_of_file) = true;
}