Çàäà÷à . Ñîðòèðîâêà ìàññèâà ñòðóêòóð

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

struct people {
string firstname, secondname;	
};

bool cmp(people first, people second) {   

}

int main() {


int N;

cin >> N;
vector<people> A (N);


    for(int i = 0; i < N; i++)
        cin>>A[i].firstname>>A[i].secondname;
        
    sort(A.begin(), A.end(), cmp );

    for(int i = 0;i< N; i ++)
      cout<<A[i].firstname<<" "<<A[i].secondname<<endl;

    
}