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>).
#!/usr/bin/python
import re
import inspect
from sys import argv, exit

def rstr():
    return input()

def rint():
    return int(input())

def rints(splitchar=' '):
    return [int(i) for i in input().split(splitchar)]

def varnames(obj, namespace=globals()):
    return [name for name in namespace if namespace[name] is obj]

def pvar(var, override=False):
    prnt(varnames(var), var, override=override)

def prnt(*args, override=False):
    if '-v' in argv or override:
        print(*args)

def get_qi(p, i, n):
    for j in range(1, n+1):
        prnt(j)
        p ^= (i % j)
    return p

if __name__ == '__main__':
    n = rint()
    p = rints()

    qs = [get_qi(p, i+1, n) for i, p in enumerate(p)]
    Q = None
    for q in qs:
        if Q is None:
            Q = q
        else:
            Q ^= q
    print(Q)
