public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  int m = sc . nextInt ( ) ;
  int [ ] a = new int [ m ] ;
  int [ ] b = new int [ m ] ;
  int [ ] count = new int [ n + 1 ] ;
  for ( int i = 0 ;
  i < m ;
  i ++ ) {
    a [ i ] = sc . nextInt ( ) ;
    b [ i ] = sc . nextInt ( ) ;
    count [ a [ i ] ] ++ ;
    count [ b [ i ] ] ++ ;
  }
  int ans = 0 ;
  boolean bre = true ;
  while ( bre ) {
    bre = false ;
    out : for ( int i = 0 ;
    i <= n ;
    i ++ ) {
      if ( count [ i ] == 1 ) {
        count [ i ] -- ;
        ans ++ ;
        for ( int j = 0 ;
        j < m ;
        j ++ ) {
          if ( a [ j ] == i ) {
            count [ b [ j ] ] -- ;
            a [ j ] = 0 ;
            b [ j ] = 0 ;
            bre = true ;
            break out ;
          }
          else if ( b [ j ] == i ) {
            count [ a [ j ] ] -- ;
            a [ j ] = 0 ;
            b [ j ] = 0 ;
            bre = true ;
            break out ;
          }
        }
      }
    }
  }
  System . out . println ( ans ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; int m = sc . nextInt ( ) ; int [ ] a = new int [ m ] ; int [ ] b = new int [ m ] ; int [ ] count = new int [ n + 1 ] ; for ( int i = 0 ; i < m ; i ++ ) { a [ i ] = sc . nextInt ( ) ; b [ i ] = sc . nextInt ( ) ; count [ a [ i ] ] ++ ; count [ b [ i ] ] ++ ; } int ans = 0 ; boolean bre = true ; while ( bre ) { bre = false ; out : for ( int i = 0 ; i <= n ; i ++ ) { if ( count [ i ] == 1 ) { count [ i ] -- ; ans ++ ; for ( int j = 0 ; j < m ; j ++ ) { if ( a [ j ] == i ) { count [ b [ j ] ] -- ; a [ j ] = 0 ; b [ j ] = 0 ; bre = true ; break out ; } else if ( b [ j ] == i ) { count [ a [ j ] ] -- ; a [ j ] = 0 ; b [ j ] = 0 ; bre = true ; break out ; } } } } } 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 (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)))) (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))))) (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))))) (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 (binary_expression left: (identifier) right: (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: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (update_expression (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))))) (expression_statement (update_expression (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (boolean_type) declarator: (variable_declarator name: (identifier) value: (true))) (while_statement condition: (parenthesized_expression (identifier)) body: (block (expression_statement (assignment_expression left: (identifier) right: (false))) (labeled_statement (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: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) consequence: (block (expression_statement (update_expression (array_access array: (identifier) index: (identifier)))) (expression_statement (update_expression (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: (block (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier))) consequence: (block (expression_statement (update_expression (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) (expression_statement (assignment_expression left: (identifier) right: (true))) (break_statement (identifier))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (identifier))) consequence: (block (expression_statement (update_expression (array_access array: (identifier) index: (array_access array: (identifier) index: (identifier))))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (decimal_integer_literal))) (expression_statement (assignment_expression left: (identifier) right: (true))) (break_statement (identifier)))))))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))