
Imports System.Console
Module Module1
    Sub Main()
        Dim n As Integer = ReadLine()
        Dim ans As Int64
        For i = 1 To n
            ans += Yakusu(i)
        Next
        WriteLine(ans)
    End Sub
    Public Function Yakusu(ByVal k As Integer) As Int64
        Dim k1 As Integer = k
        Dim r As Integer = 1
        For i = 2 To k
            Dim n As Integer = 1
            Do While k1 Mod (i ^ n) = 0
                n += 1
            Loop
            r *= n
            n -= 1
            k1 \= (i ^ n)
        Next
        Return r * k
    End Function
End Module
