def main():
  N=int(input())
  A=[0]*50000000
  ans1=0
  for i in range(1,N+1):
    if A[i-1]==1:
      continue
    ans=1
    for j in range(2,N+1):
      c=i*(j**2)
      if c>N:
        break
      else:
        A[c-1]=1
        ans+=1
    ans1+=ans*ans
  print(ans1)
main()