Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	for n := getNextInt(scanner); n > 0; n = getNextInt(scanner) {
		tt := make([]team, n)
		for i := 0; i < n; i++ {
			tt[i].id = getNextInt(scanner)
			tt[i].uni = getNextInt(scanner)
			tt[i].ac = getNextInt(scanner)
			tt[i].pn = getNextInt(scanner)
		}
		sort.SliceStable(tt, func(i, j int) bool {
			if tt[i].ac == tt[j].ac {
				if tt[i].pn == tt[j].pn {
					return tt[i].id < tt[j].id
				}
				return tt[i].pn < tt[j].pn
			}
			return tt[i].ac > tt[j].ac
		})
		cc := make([]int, 100005)
		ans := make([]int, 0)
		for i := 0; i < n; i++ {
			if cc[0] < 10 && cc[tt[i].uni] < 3 {
				cc[0]++
				cc[tt[i].uni]++
				ans = append(ans, tt[i].id)
				continue
			}
			if cc[0] < 20 && cc[tt[i].uni] < 2 {
				cc[0]++
				cc[tt[i].uni]++
				ans = append(ans, tt[i].id)
				continue
			}
			if cc[0] < 26 && cc[tt[i].uni] < 1 {
				cc[0]++
				cc[tt[i].uni]++
				ans = append(ans, tt[i].id)
				continue
			}
		}
		for i := 0; i < len(ans); i++ {
			fmt.Fprintln(writer, ans[i])
		}
	}
}

type team struct {
	id, uni, ac, pn int
}

C++: #include <iostream>
#include <algorithm>
#include <vector>
#include <map>
using namespace std;

struct team_t {
	int id, univ, accept, penalty;
	team_t(int id, int univ, int accept, int penalty)
		: id(id), univ(univ), accept(accept), penalty(penalty) {}
	bool operator<(const team_t &o) const {
		return 
			accept != o.accept ? 
			    accept > o.accept : 
			    penalty != o.penalty ? 
				    penalty < o.penalty : id < o.id;
	}
};

int main() {
	int n;
	while (cin >> n, n != 0) {
		vector<team_t> teams;
		for (int x = 0; x < n; x++) {
			int i, u, a, p;
			cin >> i >> u >> a >> p;
			teams.push_back(team_t(i, u, a, p));
		}
		sort(teams.begin(), teams.end());
		vector<team_t> selected;
		map<int, int> univ;
		for (int i = 0; i < teams.size(); i++) {
			if (selected.size() < 10 && univ[teams[i].univ] < 3) {
				selected.push_back(teams[i]);
				univ[teams[i].univ]++;
			} else if (selected.size() < 20 && univ[teams[i].univ] < 2) {
				selected.push_back(teams[i]);
				univ[teams[i].univ]++;
			} else if (selected.size() < 26 && univ[teams[i].univ] < 1) {
				selected.push_back(teams[i]);
				univ[teams[i].univ]++;
			}
		}
		for (int i = 0; i < selected.size(); i++) {
			cout << selected[i].id << endl;
		}
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <map>
#include <algorithm>
struct team{int i, u, a, p;team(int,int,int,int);};
team::team(int _i, int _u, int _a, int _p)
	:i(_i), u(_u), a(_a), p(_p) {}

bool tsort(const team& l, const team& r){
	if(l.a == r.a){
		if(l.p == r.p)return l.i < r.i;
		return l.p < r.p;
	}
	return l.a > r.a;
}

int main(){
	int n;
	while(std::cin >> n, n){
		int i, u, a, p;
		std::vector<team> v;
		while(n--){
			std::cin >> i >> u >> a >> p;
			team t = team(i, u, a, p);
			v.push_back(t);
		}
		
		std::sort(v.begin(), v.end(), tsort);
		
		int steam = 0;
		std::map<int, int> m;
		std::vector<team>::iterator it = v.begin();
		while(it != v.end()){
			int mteam;
			if(steam < 10)mteam = 3;
			else if(steam < 20)mteam = 2;
			else if(steam < 26)mteam = 1;

			if(m[(*it).u] < mteam){
				std::cout << (*it).i << std::endl;
				steam++, m[(*it).u]++;
			}
			it++;
		}
	}
}

C++: #include <bits/stdc++.h>
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define RFOR(i,a,b) for(int i=(b) - 1;i>=(a);i--)
#define REP(i,n) for(int i=0;i<(n);i++)
#define RREP(i,n) for(int i=n-1;i>=0;i--)

#define PB push_back
#define MP make_pair
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define CLR(a) memset(a,0,sizeof(a))
#define SET(a,c) memset(a,c,sizeof(a))

#define DEBUG(x) cout<<"#x"<<": "<<x<<endl

using namespace std;

typedef long long int ll;
typedef vector<int> vi;
typedef vector<ll> vl;

const ll INF = INT_MAX/3;
const ll MOD = 1000000007;
const double EPS = 1e-14;
const int dx[] = {1,0,-1,0} , dy[] = {0,1,0,-1};

map<int,bool> used;
map<int,int> count_t;
map<int,bool> isDecided;

int main(){
    while(true){
	int n;
	vector< pair< pair<int,int> , pair<int,int> > > t;
	cin >> n;
	if(n==0) break;
	used.clear();
	count_t.clear();
	isDecided.clear();
	REP(i,n){
	    int I,A,U,P;
	    cin >> I >> U >> A >> P;
	    t.PB( MP( MP(-A,P) , MP(I,U) ) );
	    used[I] = false;
	    count_t[U] = false;
	    isDecided[I] = false;
	}
	sort(ALL(t));
// 	REP(i,n) printf("A: %d P: %d I: %d U: %d\n",-t[i].first.first,t[i].first.second,t[i].second.first,t[i].second.second);
	int temp = 0;

// 	REP(i,n){
// 	    if(!used[t[i].second.second]){
// 		used[t[i].second.second] = true;
// 		count_t[t[i].second.second]++;
// 		isDecided[t[i].second.first] = true;
// 		temp++;
// 	    }
// 	}

	if(temp < 10){
	    REP(i,n){
		if(!isDecided[t[i].second.first] && count_t[t[i].second.second] < 3){
		    count_t[t[i].second.second]++;
		    isDecided[t[i].second.first] = true;
		    temp++;
		}
	    }
		if(temp == 10) break;
	}


	if(temp < 20){
	    REP(i,n){
		if(!isDecided[t[i].second.first] && count_t[t[i].second.second] < 2){
		    count_t[t[i].second.second]++;
		    isDecided[t[i].second.first] = true;
			temp++;
		}
		if(temp == 20) break;
	    }
	}

	if(temp < 26){
	    REP(i,n){
		if(!isDecided[t[i].second.second] && count_t[t[i].second.second] < 1){
		    count_t[t[i].second.second]++;
		    isDecided[t[i].second.first] = true;
		    temp++;
		}
		if(temp == 26) break;
	    }
	}

	REP(i,n){
	    if(isDecided[t[i].second.first]) cout << t[i].second.first << endl;
	}
    }

    return 0;
}