```python
def pack_entries(entries: list) -> str:
    if not isinstance(entries, list):
        raise ValueError("Argument must be a list")
    
    if not all(entries):
        return ""
    
    if not all isinstance(entries[0], list):
        raise ValueError("Each entry must be a two-element list")
    
    if not all isinstance(entries[0][ str):
        raise ValueError("Each key in each entry must a string")
    
    if not all isinstance(entries[0], str):
        raise ValueError("Each values in each entry must a string")
    
    if not all isinstance(entries[0 list, str):
        raise ValueError("Each keys in each a string")
    
    if not all isinstance(entries[0 list, str):
        raise ValueError("Each values in each entry must a string")
    
    if not all isinstance(entries[0 list, str):
        raise ValueError("Each keys in each a string")
    
    if not lists isinstance(entries[0 list, str):
        raise ValueError("Each values in each entry must a string")
    
    if not lists isinstance(entries[ 0 list, str):
        raise ValueError("Each keys in each each entry must a string")
    
    if not lists isinstance(entries[ 4 list), str):
        raise ValueError("Each keys in in each a string")
    
    if not lists isinstance(entries[ 5 list), str):
        raise ValueError("Each keys in in possible a string")
    
    if not lists isinstance(entries[ 6 list), str):
        raise ValueError("Each keys in in possible a string")

    
    if not lists isinstance(entries[ 7 list), str):
        raise ValueError("Each keys in in possible a string file
    
    if not lists isinstance(entries[ 8 list), str):
        raise ValueError("Each keys in in possible a string file")
    
    if not lists isinstance(entries[ 9 list), str):
        raise ValueError("Each keys in in possible a string file")
    
    if not lists isinstance(entries[ 10 list), str):
        raise ValueError("Each keys in in possible a string")
    
    if not lists isinstance(entries[ 11 list), str):
        raise ValueError("Each keys in in possible a string")
    
    if not lists isinstance(entries[ 12 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 13 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 14 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 15 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 16 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 17 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 18 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 19 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 10 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 11 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 12 list), str):
        raise ValueError("Each keys in in possible a string")
    
    possible not lists isinstance(entries[ 13 list), str):
