toI(s=readline()) = parse(Int,s)
toVI(s=readline()) = parse.(Int,split(s))
rep(f,n) = [f() for _ in 1:n]
@enum YN Yes=1 No=0

function main()
    n = toI()
    solve(n) |> println
end

function solve(n)
    cnt = 0
    for x in 1:n
        if 8 in digits(x)
            cnt += 1
        end
    end
    cnt
end

@static if endswith(@__FILE__, PROGRAM_FILE)
    main()
end