public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = Integer . parseInt ( sc . next ( ) ) ;
  char [ ] [ ] c = new char [ n ] [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) c [ i ] = sc . next ( ) . toCharArray ( ) ;
  for ( int i = 1 ;
  i < n - 1 ;
  i ++ ) {
    for ( int j = 1 ;
    j < n - 1 ;
    j ++ ) {
      if ( c [ i ] [ j ] == '#' && c [ i - 1 ] [ j ] == '#' && c [ i + 1 ] [ j ] == '#' && c [ i ] [ j + 1 ] == '#' && c [ i ] [ j - 1 ] == '#' ) {
        c [ i ] [ j ] = c [ i - 1 ] [ j ] = c [ i + 1 ] [ j ] = c [ i ] [ j - 1 ] = c [ i ] [ j + 1 ] = '.' ;
      }
    }
  }
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    for ( int j = 0 ;
    j < n ;
    j ++ ) {
      if ( c [ i ] [ j ] == '#' ) {
        System . out . println ( "NO" ) ;
        return ;
      }
    }
  }
  System . out . println ( "YES" ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = Integer . parseInt ( sc . next ( ) ) ; char [ ] [ ] c = new char [ n ] [ n ] ; for ( int i = 0 ; i < n ; i ++ ) c [ i ] = sc . next ( ) . toCharArray ( ) ; for ( int i = 1 ; i < n - 1 ; i ++ ) { for ( int j = 1 ; j < n - 1 ; j ++ ) { if ( c [ i ] [ j ] == ' # ' && c [ i - 1 ] [ j ] == ' # ' && c [ i + 1 ] [ j ] == ' # ' && c [ i ] [ j + 1 ] == ' # ' && c [ i ] [ j - 1 ] == ' # ' ) { c [ i ] [ j ] = c [ i - 1 ] [ j ] = c [ i + 1 ] [ j ] = c [ i ] [ j - 1 ] = c [ i ] [ j + 1 ] = ' . ' ; } } } for ( int i = 0 ; i < n ; i ++ ) { for ( int j = 0 ; j < n ; j ++ ) { if ( c [ i ] [ j ] == ' # ' ) { System . out . println ( " NO " ) ; return ; } } } System . out . println ( " YES " ) ; }
(method_declaration (modifiers) type: (void_type) name: (identifier) parameters: (formal_parameters (formal_parameter type: (array_type element: (type_identifier) dimensions: (dimensions)) name: (identifier))) body: (block (local_variable_declaration type: (type_identifier) declarator: (variable_declarator name: (identifier) value: (object_creation_expression type: (type_identifier) arguments: (argument_list (field_access object: (identifier) field: (identifier)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))))) (local_variable_declaration type: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier)) dimensions: (dimensions_expr (identifier))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) name: (identifier) arguments: (argument_list))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) update: (update_expression (identifier)) body: (block (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal))) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (binary_expression left: (binary_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (character_literal)) right: (binary_expression left: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (identifier)) right: (character_literal))) right: (binary_expression left: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (identifier)) right: (character_literal))) right: (binary_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (character_literal))) right: (binary_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (character_literal)))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (assignment_expression left: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (identifier)) right: (assignment_expression left: (array_access array: (array_access array: (identifier) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) index: (identifier)) right: (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (assignment_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (binary_expression left: (identifier) right: (decimal_integer_literal))) right: (character_literal))))))))))))) (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (for_statement init: (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) condition: (binary_expression left: (identifier) right: (identifier)) update: (update_expression (identifier)) body: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (array_access array: (identifier) index: (identifier)) index: (identifier)) right: (character_literal))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))) (return_statement))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal))))))