let words s =
    let r = Str.regexp " +" in
    Str.split r s

let min_num_of_ops n xs =
	let rec mnoo t = function
		[] -> t
		| y :: ys -> match y with
			t -> mnoo (t - 1) ys
			| _ -> mnoo t ys
	in mnoo n (List.rev xs)
		
let () =
    let n = read_int () in
    let xs = List.map int_of_string (words (read_line ())) in
    let ans = min_num_of_ops n xs in
    print_int ans