pizzen <- list(
Margherita = c("Tomaten", "Kaese"),
Cardinale = c("Tomaten", "Kaese", "Schinken"),
"San Romio" = c("Tomaten", "Kaese","Schinken", "Salami", "Mais"),
Provinciale = c("Tomaten", "Kaese","Schinken", "Mais", "Pfefferoni")
)
but it does not mark every row with numbers 1,2,3,4... so I am not sure about the format