People in the Tomskaya region like magic formulas very much. You can see some of them below.

Imagine you are given a sequence of positive integer numbers *p*<sub class="lower-index">1</sub>, *p*<sub class="lower-index">2</sub>, ..., *p*<sub class="lower-index">*n*</sub>. Lets write down some magic formulas:

Here, "mod" means the operation of taking the residue after dividing.

The expression <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/b364f2e04c665b78b924ec10666327a4ef4635bc.png" style="max-width: 100.0%;max-height: 100.0%;"/> means applying the bitwise *xor* (excluding "OR") operation to integers *x* and *y*. The given operation exists in all modern programming languages. For example, in languages C++ and Java it is represented by "^", in Pascal — by "xor".

People in the Tomskaya region like magic formulas very much, but they don't like to calculate them! Therefore you are given the sequence *p*, calculate the value of *Q*.
The first line of the input contains the only integer *n* (1 ≤ *n* ≤ 10<sup class="upper-index">6</sup>). The next line contains *n* integers: *p*<sub class="lower-index">1</sub>, *p*<sub class="lower-index">2</sub>, ..., *p*<sub class="lower-index">*n*</sub> (0 ≤ *p*<sub class="lower-index">*i*</sub> ≤ 2·10<sup class="upper-index">9</sup>).
import sys, re

#f = open('..\\input.txt','r')
f = sys.stdin

n, ret = int(raw_input()), 0
 
data = map(int, raw_input().split())
 
for i in xrange(n):
  ret = ret ^ data[i]

def calcXOR(n):
  xr = 0
  while (n & 3) != 3:
    xr = xr ^ n
    n = n - 1
  return xr

def calc(n, mod):
  k, xr = n / mod, 0
  if k % 2 == 1:
    xr = xr ^ calcXOR(mod - 1)

  xr = xr ^ calcXOR(n % mod)

  return xr
 
for i in xrange(n):
  ret = ret ^ calc(n, i + 1)

print ret