from typing import Dict, Optional

class Validate:
    def __init__( self, text: str ) -> None:
        self.text = text
        self.idx = 0
        self.error = False
        self.top()

    def eof( self ) -> bool:
        return self.error or self.idx >= len( self.text )

    def peek( self ) -> str:
        if self.eof():
            return ''
        else:
            return self.text[ self.idx ]

    def shift( self ) -> str:
        x = self.peek()
        self.idx += 1
        return x

    def require( self, x: str ) -> None:
        check = self.text[ self.idx : self.idx + len( x ) ]
        if check != x:
            self.error = True
        self.idx += len( x )

    def top( self ) -> None:
        while not self.eof():
            self.stmt()

    def stmt( self ) -> None:
        if self.peek() == 'n':
            self.server()
            self.spaces()
        if self.peek() == '\n':
            self.shift()
        else:
            self.comment()

    def comment( self ) -> None:
        self.spaces()
        self.require( '#' )
        while not self.eof() and self.peek() != '\n':
            self.shift()
        self.require( '\n' )

    def spaces( self, req: bool = False ) -> bool:
        if not self.peek().isspace():
            if req:
                self.error = True
            return False

        while self.peek().isspace() and self.peek() != '\n':
            self.shift()
        return True

    def server( self ) -> None:
        self.require( 'nameserver' )
        self.spaces( True )
        self.address()

    def address( self ) -> None:
        self.num()
        for i in range( 3 ):
            self.require( '.' )
            self.num()

    def num( self ) -> None:
        x = self.shift()

        if x == '0':
            return

        if not x.isdecimal():
            self.error = True
        while self.peek().isdecimal():
            self.shift()

    def ok( self ) -> bool:
        return not self.error


def resolv_valid( text: str ) -> bool:
    return Validate( text ).ok()

import run_tests