public static void main ( String [ ] args ) throws IOException {
  Scanner sc = new Scanner ( System . in ) ;
  int t = sc . nextInt ( ) ;
  while ( t -- > 0 ) {
    int n = sc . nextInt ( ) ;
    boolean [ ] matched = new boolean [ n + 1 ] ;
    int extra = 0 ;
    int [ ] array = new int [ n + 1 ] ;
    int pair = 0 ;
    boolean [ ] daughter = new boolean [ n + 1 ] ;
    int boy = - 1 ;
    int girl = - 1 ;
    int left = 0 ;
    int index = - 1 ;
    for ( int i = 1 ;
    i <= n ;
    i ++ ) {
      int k = sc . nextInt ( ) ;
      boolean found = false ;
      while ( k > 0 ) {
        int prince = sc . nextInt ( ) ;
        if ( matched [ prince ] == false && daughter [ i ] == false ) {
          matched [ prince ] = true ;
          daughter [ i ] = true ;
          pair ++ ;
          array [ prince ] = - 1 ;
          found = true ;
          k -- ;
          continue ;
        }
        k -- ;
      }
      if ( found == false ) {
        left ++ ;
        index = i ;
      }
    }
    int b = - 1 ;
    if ( left > 0 ) {
      for ( int i = 1 ;
      i <= n ;
      i ++ ) {
        if ( array [ i ] == 0 ) {
          b = i ;
          break ;
        }
      }
    }
    if ( left > 0 && b != - 1 ) {
      System . out . println ( "IMPROVE" ) ;
      System . out . println ( index + " " + b ) ;
    }
    else {
      System . out . println ( "OPTIMAL" ) ;
    }
  }
}

public static void main ( String [ ] args ) throws IOException { Scanner sc = new Scanner ( System . in ) ; int t = sc . nextInt ( ) ; while ( t -- > 0 ) { int n = sc . nextInt ( ) ; boolean [ ] matched = new boolean [ n + 1 ] ; int extra = 0 ; int [ ] array = new int [ n + 1 ] ; int pair = 0 ; boolean [ ] daughter = new boolean [ n + 1 ] ; int boy = - 1 ; int girl = - 1 ; int left = 0 ; int index = - 1 ; for ( int i = 1 ; i <= n ; i ++ ) { int k = sc . nextInt ( ) ; boolean found = false ; while ( k > 0 ) { int prince = sc . nextInt ( ) ; if ( matched [ prince ] == false && daughter [ i ] == false ) { matched [ prince ] = true ; daughter [ i ] = true ; pair ++ ; array [ prince ] = - 1 ; found = true ; k -- ; continue ; } k -- ; } if ( found == false ) { left ++ ; index = i ; } } int b = - 1 ; if ( left > 0 ) { for ( int i = 1 ; i <= n ; i ++ ) { if ( array [ i ] == 0 ) { b = i ; break ; } } } if ( left > 0 && b != - 1 ) { System . out . println ( " IMPROVE " ) ; System . out . println ( index + " ▁ " + b ) ; } else { System . out . println ( " OPTIMAL " ) ; } } }
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(identifier) name: (identifier) arguments: (argument_list)))) (local_variable_declaration type: (array_type element: (boolean_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (boolean_type) dimensions: (dimensions_expr (binary_expression left: (identifier) right: (decimal_integer_literal)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (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)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (decimal_integer_literal))) (local_variable_declaration type: (array_type element: (boolean_type) dimensions: (dimensions)) declarator: (variable_declarator name: (identifier) value: (array_creation_expression type: (boolean_type) dimensions: (dimensions_expr (binary_expression left: (identifier) right: (decimal_integer_literal)))))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (decimal_integer_literal)))) (local_variable_declaration type: (integral_type) declarator: (variable_declarator name: (identifier) value: (unary_expression operand: (decimal_integer_literal)))) (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: (unary_expression operand: (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 (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: (boolean_type) declarator: (variable_declarator name: (identifier) value: (false))) (while_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (decimal_integer_literal))) 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: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (false)) right: (binary_expression left: (array_access array: (identifier) index: (identifier)) right: (false)))) consequence: (block (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (true))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (true))) (expression_statement (update_expression (identifier))) (expression_statement (assignment_expression left: (array_access array: (identifier) index: (identifier)) right: (unary_expression operand: (decimal_integer_literal)))) (expression_statement (assignment_expression left: (identifier) right: (true))) (expression_statement (update_expression (identifier))) (continue_statement))) (expression_statement (update_expression (identifier))))) (if_statement condition: (parenthesized_expression (binary_expression left: (identifier) right: (false))) consequence: (block (expression_statement (update_expression 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(if_statement condition: (parenthesized_expression (binary_expression left: (binary_expression left: (identifier) right: (decimal_integer_literal)) right: (binary_expression left: (identifier) right: (unary_expression operand: (decimal_integer_literal))))) consequence: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal)))) (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (binary_expression left: (binary_expression left: (identifier) right: (string_literal)) right: (identifier)))))) alternative: (block (expression_statement (method_invocation object: (field_access object: (identifier) field: (identifier)) name: (identifier) arguments: (argument_list (string_literal))))))))))