main::IO()
main = do
  nc<-getLine
  let n = read nc ::Int
  dat<-(get_n n)
  print (solver 1 dat)



solver :: Int -> [Int] -> Int
solver x [] = 0
solver x (b:rest)= let b_rest = (if mod b x == 0 then x else mod b x) in
                   let buys   = div (b-b_rest) x in
                   let next_p = max x (b_rest+1) in
                   buys + (solver next_p rest)

get_n::Int -> IO [Int]
get_n 0 = return []
get_n n = do
          c<-getLine
          let m = read c ::Int
          rest<- (get_n (n-1))
          return (m:rest)