public static void main ( String [ ] args ) {
  Scanner sc = new Scanner ( System . in ) ;
  int n = sc . nextInt ( ) ;
  long [ ] a = new long [ n ] ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) a [ i ] = sc . nextLong ( ) ;
  sc . close ( ) ;
  long count1 = 0 ;
  long sum = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    sum += a [ i ] ;
    if ( i % 2 == 0 && sum <= 0 ) {
      count1 += 1 - sum ;
      sum = 1 ;
    }
    else if ( i % 2 == 1 && sum >= 0 ) {
      count1 += sum + 1 ;
      sum = - 1 ;
    }
  }
  sum = 0 ;
  long count2 = 0 ;
  for ( int i = 0 ;
  i < n ;
  i ++ ) {
    sum += a [ i ] ;
    if ( i % 2 == 1 && sum <= 0 ) {
      count2 += 1 - sum ;
      sum = 1 ;
    }
    else if ( i % 2 == 0 && sum >= 0 ) {
      count2 += sum + 1 ;
      sum = - 1 ;
    }
  }
  System . out . println ( Math . min ( count1 , count2 ) ) ;
}

public static void main ( String [ ] args ) { Scanner sc = new Scanner ( System . in ) ; int n = sc . nextInt ( ) ; long [ ] a = new long [ n ] ; for ( int i = 0 ; i < n ; i ++ ) a [ i ] = sc . nextLong ( ) ; sc . close ( ) ; long count1 = 0 ; long sum = 0 ; for ( int i = 0 ; i < n ; i ++ ) { sum += a [ i ] ; if ( i % 2 == 0 && sum <= 0 ) { count1 += 1 - sum ; sum = 1 ; } else if ( i % 2 == 1 && sum >= 0 ) { count1 += sum + 1 ; sum = - 1 ; } } sum = 0 ; long count2 = 0 ; for ( int i = 0 ; i < n ; i ++ ) { sum += a [ i ] ; if ( i % 2 == 1 && sum <= 0 ) { count2 += 1 - sum ; sum = 1 ; } else if ( i % 2 == 0 && sum >= 0 ) { count2 += sum + 1 ; sum = - 1 ; } } System . out . println ( Math . min ( count1 , count2 ) ) ; }
(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: (array_type element: (integral_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (integral_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: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))))) (expression_statement (method_invocation object: (identifier) name: (identifier) arguments: (argument_list))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (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: (identifier) right: (array_access array: (identifier) index: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (decimal_integer_literal) right: (identifier)))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (identifier) right: (unary_expression operand: (decimal_integer_literal))))))))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal))) (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: (identifier) right: (array_access array: (identifier) index: (identifier)))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (decimal_integer_literal) right: (identifier)))) (expression_statement (assignment_expression left: (identifier) right: (decimal_integer_literal)))) alternative: (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) consequence: (block (expression_statement (assignment_expression left: (identifier) right: (binary_expression left: (identifier) right: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (identifier) right: (unary_expression operand: (decimal_integer_literal))))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (identifier))))))))