well i put them as Destino(Density) Origen(Country)
this is the query i try
LOAD CSV WITH HEADERS FROM "file:///relacion.csv" as line with line where line.id_tipo="OUTFLOW"
MERGE(des:Destino{id: line.pai_id_pais})
MERGE(ori:Origen{id: line.id_pais})
MERGE (ori)<-[:OUTFLOW]-(des)