open System
    
[<EntryPoint>]
let main args =    
    let s = Console.ReadLine().Split(' ');
    let N = Int64.Parse(s.[0])
    
    let z = 2L * (N / 5L + N / 3L - N / 15L) + N / 15L * 2L 
    printfn "%d" z
    0