find last row per each column of dataframe

I have the following dataframe and i want to get a vector that contains the last non NA row of each column

df <- data.frame(a = 1:5, b = 6:10, c = c(rep(NA, 5)))
df <- rbind(df, rep(NA, ncol(df)), rep(NA, ncol(df)))
df[2,] <- NA
df$b[6]<-8

df
   a  b  c
1  1  6 NA
2 NA NA NA
3  3  8 NA
4  4  9 NA
5  5 10 NA
6 NA  8 NA
7 NA NA NA

the vector im looking would be:

c(5,6,0)

how can i achieve this using base r? i have the following formula but throws me warnings:

apply(row(df) + 0 * df, 2, function(x) max(x, na.rm = TRUE))

thanks

>Solution :

sapply(df, function(z) c(rev(which(!is.na(z))), 0)[1])
# a b c 
# 5 6 0