public static void main ( String [ ] args ) {
  Scanner scan = new Scanner ( System . in ) ;
  int a = scan . nextInt ( ) ;
  int b [ ] = new int [ a ] ;
  int count = 0 ;
  for ( int i = 0 ;
  i != a ;
  i ++ ) {
    b [ i ] = scan . nextInt ( ) ;
    count += b [ i ] ;
  }
  if ( count % a != 0 ) {
    System . out . println ( - 1 ) ;
  }
  else {
    int ans2 = count / a ;
    count = 0 ;
    int ans = 0 ;
    for ( int i = 0 ;
    i != a ;
    i ++ ) {
      count += b [ i ] ;
      if ( count != ans2 * ( i + 1 ) ) {
        ans ++ ;
      }
    }
    System . out . println ( ans ) ;
  }
}

public static void main ( String [ ] args ) { Scanner scan = new Scanner ( System . in ) ; int a = scan . nextInt ( ) ; int b [ ] = new int [ a ] ; int count = 0 ; for ( int i = 0 ; i != a ; i ++ ) { b [ i ] = scan . nextInt ( ) ; count += b [ i ] ; } if ( count % a != 0 ) { System . out . println ( - 1 ) ; } else { int ans2 = count / a ; count = 0 ; int ans = 0 ; for ( int i = 0 ; i != a ; i ++ ) { count += b [ i ] ; if ( count != ans2 * ( i + 1 ) ) { ans ++ ; } } 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) dimensions: (dimensions) value: (array_creation_expression type: (integral_type) dimensions: (dimensions_expr (identifier))))) (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: (identifier) index: (identifier)) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (expression_statement (assignment_expression left: (identifier) right: (array_access array: (identifier) index: (identifier)))))) (if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (identifier)) right: (decimal_integer_literal))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (unary_expression operand: (decimal_integer_literal)))))) alternative: (block (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (binary_expression left: (identifier) right: (identifier)))) (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: (identifier) right: (binary_expression left: (identifier) right: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal)))))) consequence: (block (expression_statement (update_expression (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))))