query: PREFIX gas: <http://www.bigdata.com/rdf/gas#>
  
  SELECT ?super (?aLength + ?bLength as ?length) WHERE {
    SERVICE gas:service {
      gas:program gas:gasClass "com.bigdata.rdf.graph.analytics.SSSP" ;
                  gas:in wd:Q5 ;
      gas:traversalDirection "Forward" ;
                             gas:out ?super ;
                             gas:out1 ?aLength ;
                             gas:maxIterations 10 ;
      gas:linkType wdt:P279 .
    }
    SERVICE gas:service {
      gas:program gas:gasClass "com.bigdata.rdf.graph.analytics.SSSP" ;
                  gas:in wd:Q15773347 ;
      gas:traversalDirection "Forward" ;
                             gas:out ?super ;
                             gas:out1 ?bLength ;
                             gas:maxIterations 10 ;
      gas:linkType wdt:P279 .
    }  
  } ORDER BY ?length
  LIMIT 1