View Code of Problem 3929

#include<stdio.h>
int main() 
    {
	   	int n,i,tmp,res,m;
	       	scanf("%d",&n);
	       	while(n--){
	       		scanf("%d",&m);
	       		res=0;
	       		for(i=0;i<m;++i){
	       			scanf("%d",&tmp);
	       			res=res^tmp; 
	       		}
	       		printf("%d\n",res);
	       	}
	       	return 0; 
	     }