//采用增强for循环，vector

#include <bits/stdc++.h>
using namespace std;

struct Student{
    int id;
    int grade;
};

bool cmp(Student a , Student b){
    if(a.grade == b.grade) return a.id < b.id;
    else return a.grade < b.grade;
}
int main(){
    int n;
    cin >> n;
    vector<Student> stu(n);
    for(auto& a : stu){
        cin >> a.id >> a.grade;
    }
    sort(stu.begin(),stu.end(),cmp);
    for(const auto& a : stu){
        cout << a.id << " " << a.grade << endl;
    }
    return 0;
}

//采用for循环，vector

#include <bits/stdc++.h>
using namespace std;

struct Student{
    int id;
    int grade;
};

bool cmp(Student a , Student b){
    if(a.grade == b.gra...