The number of the odd number of csuoj 1217

Description

Given some numbers, only one of these numbers appears an odd number and finds this number.

 

Input

The first line N of each group of data indicates the number of numbers, 1 <= n <= 2 ^ 18 and N % 2 = 1.

Each row in the next n rows contains a 32-bit signed integer.

 

Output

The number that appears for an odd number of times. Each group of data corresponds to a row.

 

Sample Input

51122371212233

Sample output

32

I read the code of the great god and used bitwise O (arithmetic □arithmetic) O

1 # include <stdio. h> 2 int main () 3 {4 int n, x, ans; 5 while (scanf ("% d", & N )! = EOF) 6 {7 ans = 0; 8 for (; n> 0; -- N) 9 {10 scanf ("% d", & X ); 11 ans ^ = x; 12} 13 printf ("% d \ n", ANS); 14} 15 return 0; 16}