int aktualizace(const char* jmeno)
{
    FILE *f = fopen(jmeno, "rb+");
    if(!f) return EOF;
    int i;
    while(fread(&i, sizeof(int), 1, f) == 1)
    {
        if(i%2 == 0)
        {
            i /=2;
            fseek(f,-(long)sizeof(int), SEEK_CUR);
            fwrite(&i, sizeof(int), 1, f);
            fseek(f, 0, SEEK_CUR);
        }
    }
    fclose(f);
    return 0;
}
