Problem:
Score: 300 points

Problem Statement

In Republic of Atcoder, there are N prefectures, and a total of M cities that belong to those prefectures.

City i is established in year Y_i and belongs to Prefecture P_i.

You can assume that there are no multiple cities that are established in the same year.

It is decided to allocate a 12-digit ID number to each city.

If City i is the x-th established city among the cities that belong to Prefecture i, the first six digits of the ID number of City i is P_i, and the last six digits of the ID number is x.

Here, if P_i or x (or both) has less than six digits, zeros are added to the left until it has six digits.

Find the ID numbers for all the cities.

Note that there can be a prefecture with no cities.

Constraints

1 \leq N \leq 10^5

1 \leq M \leq 10^5

1 \leq P_i \leq N

1 \leq Y_i \leq 10^9

Y_i are all different.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N M
P_1 Y_1
:
P_M Y_M

Output

Print the ID numbers for all the cities, in ascending order of indices (City 1, City 2, ...).

Sample Input 1

2 3
1 32
2 63
1 12

Sample Output 1

000001000002
000002000001
000001000001

As City 1 is the second established city among the cities that belong to Prefecture 1, its ID number is 000001000002.

As City 2 is the first established city among the cities that belong to Prefecture 2, its ID number is 000002000001.

As City 3 is the first established city among the cities that belong to Prefecture 1, its ID number is 000001000001.

Sample Input 2

2 3
2 55
2 77
2 99

Sample Output 2

000002000001
000002000002
000002000003

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n;i>0;i--)
#define rep1(i,s,n) for(int i=s;i<n;i++)
#define max0(a,b,c) max(max(a,b),c)
#define min0(a,b,c) min(min(a,b),c)
#define ft first
#define sc second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define all(v) (v).begin(),(v).end()
using namespace std;
using Graph = vector<vector<int>>;
typedef long long lint;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ldouble;
typedef vector<int> vec;
typedef vector<ll> lvec;
typedef vector<ull> ulvec;
typedef vector<pair<int,int>> pvec;
typedef vector<pair<ll,ll>> plvec;
typedef vector<tuple<ll,ll,ll>> tvec;
typedef vector<string> svec;

int main(){
    ll n,m;
    cin>>n>>m;
    vector<tuple<ll,ll,ll>> tp(m);
    rep(i,m){
        ll p,y;
        cin>>p>>y;
        tp[i]=mt(p,y,i);
    }
    sort(all(tp));
    vector<pair<ll,string>> P(m);
    ll cnt=1;
    rep(i,m){
        ll t=get<0>(tp[i]),digit=0;
        while(t!=0){
            digit++;
            t/=10;
        }
        rep(j,6-digit) P[i].sc+='0';
        P[i].sc+=to_string(get<0>(tp[i]));
        t=cnt;
        digit=0;
        while(t!=0){
            digit++;
            t/=10;
        }
        rep(j,6-digit) P[i].sc+='0';
        P[i].sc+=to_string(cnt);
        P[i].ft=get<2>(tp[i]);
        if(i<m-1){
            if(get<0>(tp[i])==get<0>(tp[i+1])) cnt++;
            else cnt=1;
        }
    }
    sort(all(P));
    rep(i,m) cout<<P[i].sc<<endl;
}