The input consists of four lines, each line containing a single digit 0 or 1.
none
0
1
1
0
0
0
0
0
0
0
1
0
0
0
1
0
1
0
0
0
1
1
0
0
1
0
0
1
0
0
1
0
1
0
0
1
1
1
0
1
0
0
0
1
1
1
0
0
1
1
0
1
0
1
0
1
1
0
1
0
0
0
1
1
1
1
0
1
1
1
0
1
1
1
0
1
1
1
1
1

a=int(input())
b=int(input())
c=int(input())
d=int(input())
print(a^b^c^d)