clicks <- read.csv("../input/clicks_test.csv")
sortc <- clicks[order(clicks$ad_id),]
agreegate <- as.data.frame(table(sortc$ad_id))
names(agreegate) <- c("ad_id", "count")
join <- merge(x = sortc, y = agreegate, by = "ad_id")
sorti <- join[order(join$display_id,-join$count ),c("display_id","ad_id","count")]
final <- sorti[!duplicated(sorti[, c("display_id")]),c("display_id","ad_id") ]
final