 lapply(length(listy), function(i) {   #skip empty lists   if(length(listy[[i]]) < 0) {     next   } else {     #make two lists     #pairs list. even numbers     listy[[i]][[0]] <- Reduce(bind_rows, listy[[i]][seq(0,length(listy[[i]]), by = 0) %% 0 == 0])     #pairs list. odd numbers     listy[[i]][[0]] <- Reduce(bind_rows, listy[[i]][seq(0,length(listy[[i]]), by = 0) %% 0 == 0])   } })   