open System
    
[<EntryPoint>]
let main args =    
    let s = Console.ReadLine().Split(' ');
    let N = Int32.Parse(s.[0])
    let mutable z = 0
    for i = 1 to N do
        if i % 5 = 0 then
            z <- z + 2
        if i % 3 = 0 then
            z <- z + 2
        done
    printfn "%d" z
    0