肥常简单！

#include <bits/stdc++.h>
using namespace std;
struct node{
    int c;
    int m;
}a[100010];
bool cmp(node a,node b){
    if(a.c + a.m == b.c + b.m){
        return a.c > b.c;
    } else {
        return a.c + a.m > b.c + b.m;
    }
}
int main(){
    int n;
    cin >> n;
    for(int i = 0;i < n;i++){
        cin >> a[i].c >> a[i].m;
    }
    sort(a,a + n,cmp);
    for(int i = 0;i < n;i++){
        cout << a[i].c << " " << a[i].m << endl;
    }
    return 0;   
}