B. Qualifying Contest_ Sort

B. Qualifying ContestTime limit per test1 secondmemory limit per test256 megabytesinputstandard inputoutputstandard output

Very soon Berland would hold a School Team programming Olympiad. From each of the m Berland regions A team of the people are invited to participate in the Olympiad. The qualifying contest to form teams is held and it is attended by N berland students. There were at least, schoolboys participating from each of the m regions of Berland. The result of each of the participants of the qualifying competition is a integer score from 0 to inclusive.< /c8>

The team of each of the such members of the qualifying competition in the region, and that none of the them Can is replaced by a schoolboy of the same region, not included in the team and who received A greater number of points. There may was a situation where a team of some region can isn't being formed uniquely, that's, there is more than one school te Am that meets the properties described above. In this case, the region needs to undertake an additional contest. The "teams in the" considered to be different if there was at least one schoolboy who was included in one team And is not a included in the other team. It is guaranteed this for each region at least and its representatives participated in the qualifying contest.

Your task is, given the results of the qualifying competition, to identify the team from each region, or to announce that Formation requires additional contests.

Input

The first line of the input contains the integers n and m (2≤ n ≤100, 1≤ m ≤10, n ≥2m)-the number of participants of the qualifying contest and the Numbe R of Regions in Berland.

Next n lines contain the description of the participants of the qualifying contest in the following format:s Urname (a string of length from 1to characters and consisting of large and small 中文版 letters), Region Numbe R (integer from 1 to m) and the number of points scored by the participant (integer from 0 to 800 , inclusive).

It is guaranteed this all surnames of the participants be distinct and at least, people participated from each of The m regions. The surnames that is differ in letter cases, should is considered distinct.

Output

Print m lines. On the i-th line print the team of the i-th region-the surnames of the both team members Arbitrary order, or a single character "?" (without the quotes) if you need to spend further qualifying contests in the region.

Examplesinput

5 2
Ivanov 1 763
Andreev 2 800
Petrov 1 595
Sidorov 1 790
Semenov 2 503

Output

Sidorov Ivanov
Andreev Semenov

Input

5 2
Ivanov 1 800
Andreev 2 763
Petrov 1 800
Sidorov 1 800
Semenov 2 503

Output

?
Andreev Semenov

Problem Solving Report:

1, the topic is very simple, is to see test instructions, the idea output Oh!

#include <map>#include<stack>#include<vector>#include<queue>#include<Set>#include<cmath>#include<cstdio>#include<cstdlib>#include<iostream>#include<algorithm>#include<string>using namespaceStd;typedefLong LongLl;vector<pair<int,string> > v[100005];intn,m;BOOLcmpConstpair<int,string>&a,Constpair<int,string>&b) {    if(a.first==B.first)returnA.second>B.second; Else returnA.first>B.first;}intMain () {scanf ("%d%d",&n,&m);  for(intI=1; i<=n;i++) v[i].clear ();  for(intI=1; i<=n;i++)    {        intId,score; Charname[ -]; scanf ("%s%d%d",name,&id,&score);    V[id].push_back (Make_pair (score,name)); }     for(intI=1; i<=m;i++) sort (V[i].begin (), V[i].end (), CMP);  for(intI=1; i<=m;i++)    {        if(v[i][0].first==v[i][1].first) {if(v[i].size () = =2|| v[i][1].first>v[i][2].first) printf ("%s%s\n", v[i][0].second.c_str (), v[i][1].second.c_str ()); ElsePuts"?"); Continue; }        if(v[i].size () = =2|| v[i][1].first>v[i][2].first) printf ("%s%s\n", v[i][0].second.c_str (), v[i][1].second.c_str ()); ElsePuts"?"); }    return 0;}

B. Qualifying Contest_ Sort