Who preceded and who followed Charles the Fat as emperor of Occident?
SELECT ?value1 ?value2 WHERE { wd:Q150712 p:P97 ?s . ?s ps:P97 wd:Q23906200 . ?s pq:P155 ?value1 . ?s pq:P156 ?value2 }
charles the fat: Q150712 emperor of occident: Q23906200