public static void main ( String [ ] args ) {
  n = scanner . nextInt ( ) ;
  int m = scanner . nextInt ( ) ;
  int [ ] a = new int [ m ] , b = new int [ m ] ;
  graph = new boolean [ n ] [ n ] ;
  visited = new boolean [ n ] ;
  for ( int i = 0 ;
  i < m ;
  i ++ ) graph [ a [ i ] = scanner . nextInt ( ) - 1 ] [ b [ i ] = scanner . nextInt ( ) - 1 ] = graph [ b [ i ] ] [ a [ i ] ] = true ;
  int ans = 0 ;
  for ( int i = 0 ;
  i < m ;
  i ++ ) {
    graph [ a [ i ] ] [ b [ i ] ] = graph [ b [ i ] ] [ a [ i ] ] = false ;
    Arrays . fill ( visited , false ) ;
    dfs ( 0 ) ;
    if ( IntStream . range ( 0 , n ) . anyMatch ( j -> ! visited [ j ] ) ) ans ++ ;
    graph [ a [ i ] ] [ b [ i ] ] = graph [ b [ i ] ] [ a [ i ] ] = true ;
  }
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { n = scanner . nextInt ( ) ; int m = scanner . nextInt ( ) ; int [ ] a = new int [ m ] , b = new int [ m ] ; graph = new boolean [ n ] [ n ] ; visited = new boolean [ n ] ; for ( int i = 0 ; i < m ; i ++ ) graph [ a [ i ] = scanner . nextInt ( ) - 1 ] [ b [ i ] = scanner . nextInt ( ) - 1 ] = graph [ b [ i ] ] [ a [ i ] ] = true ; int ans = 0 ; for ( int i = 0 ; i < m ; i ++ ) { graph [ a [ i ] ] [ b [ i ] ] = graph [ b [ i ] ] [ a [ i ] ] = false ; Arrays . fill ( visited , false ) ; dfs ( 0 ) ; if ( IntStream . range ( 0 , n ) . anyMatch ( j -> ! visited [ j ] ) ) ans ++ ; graph [ a [ i ] ] [ b [ i ] ] = graph [ b [ i ] ] [ a [ i ] ] = true ; } System . out . println ( ans ) ; }
(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 (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (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)))) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (array_creation_expression type: (boolean_type) dimensions: (dimensions_expr (identifier)) dimensions: (dimensions_expr (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (array_creation_expression type: (boolean_type) 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: (array_access array: (identifier) index: (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))) index: (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (binary_expression left: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)) right: (decimal_integer_literal)))) right: (assignment_expression left: (array_access array: (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))) index: (array_access array: (identifier) index: (identifier))) right: (true))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_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 (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))) index: (array_access array: (identifier) index: (identifier))) right: (assignment_expression left: (array_access array: (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))) index: (array_access array: (identifier) index: (identifier))) right: (false)))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (false)))) (expression_statement (method_invocation name: (identifier) arguments: (argument_list (decimal_integer_literal)))) (if_statement condition: (parenthesized_expression (method_invocation object: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (decimal_integer_literal) (identifier))) name: (identifier) arguments: (argument_list (lambda_expression parameters: (identifier) body: (unary_expression operand: (array_access array: (identifier) index: (identifier))))))) consequence: (expression_statement (update_expression (identifier)))) (expression_statement (assignment_expression left: (array_access array: (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))) index: (array_access array: (identifier) index: (identifier))) right: (assignment_expression left: (array_access array: (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))) index: (array_access array: (identifier) index: (identifier))) right: (true)))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))