public static void main ( String [ ] args ) {
  Scanner in = new Scanner ( System . in ) ;
  int T = in . nextInt ( ) ;
  for ( int t = 0 ;
  t < T ;
  t ++ ) {
    int R = in . nextInt ( ) ;
    int C = in . nextInt ( ) ;
    int sum = 0 ;
    int min = Integer . MAX_VALUE ;
    int negative = 0 ;
    for ( int r = 0 ;
    r < R ;
    r ++ ) {
      for ( int c = 0 ;
      c < C ;
      c ++ ) {
        int a = in . nextInt ( ) ;
        if ( a < 0 ) {
          negative ++ ;
        }
        a = Math . abs ( a ) ;
        sum += a ;
        min = Math . min ( min , a ) ;
      }
    }
    int answer = ( negative % 2 == 0 ) ? sum : ( sum - 2 * min ) ;
    System . out . println ( answer ) ;
  }
}

public static void main ( String [ ] args ) { Scanner in = new Scanner ( System . in ) ; int T = in . nextInt ( ) ; for ( int t = 0 ; t < T ; t ++ ) { int R = in . nextInt ( ) ; int C = in . nextInt ( ) ; int sum = 0 ; int min = Integer . MAX_VALUE ; int negative = 0 ; for ( int r = 0 ; r < R ; r ++ ) { for ( int c = 0 ; c < C ; c ++ ) { int a = in . nextInt ( ) ; if ( a < 0 ) { negative ++ ; } a = Math . abs ( a ) ; sum += a ; min = Math . min ( min , a ) ; } } int answer = ( negative % 2 == 0 ) ? sum : ( sum - 2 * min ) ; System . out . println ( answer ) ; } }
(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)))) (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 (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: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (field_access object: (identifier) field: (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 (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 (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list)))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) consequence: (block (expression_statement (update_expression (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier))))) (expression_statement (assignment_expression left: (identifier) right: (identifier))) (expression_statement (assignment_expression left: (identifier) right: (method_invocation object: (identifier) name: (identifier) arguments: (argument_list (identifier) (identifier))))))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (ternary_expression condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (decimal_integer_literal))) consequence: (identifier) alternative: (parenthesized_expression (binary_expression left: (identifier) right: (binary_expression left: (decimal_integer_literal) right: (identifier))))))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (identifier))))))))