#include<iostream>
#include<vector>
intfindSingleELement(const std::vector<int>&arr){
    int result=0;
    for(int num :arr){
        result ^=num;
    }
    return result;
}
int main(){
    std::vector<int> arr1={1,2,3,4,1,2,4};
    std::cout<<"Sample Output 1:"<<findSingleELement(arr1)<<std::endl;
    
    std::vector<int> arr2 ={700,300,500,300,700};
    std::cout<<"Sample Output 2:"<<endl;
    return 0;
}