#!/usr/bin/python
from sys import argv
mem = [{}, {}]
def flip(x, y):
if y not in mem[x]:
mem[x][y] = 1
else:
mem[x][y] = 1 - mem[x][y]
return mem[x][y]
with open(argv[1]) as f:
for line in f.readlines():
l = list(map(int, line.split()))
x = l[0]
for i in range(1, len(l)):
x = flip(x, l[i])
print(x)