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 JavaScript (node.js v5.12) (judge verdict: Accepted)

function length_plus(moji){
    moji = String(moji);
    while(moji.length < 6){
        moji = "0" + moji;
    }
    return(moji);
}
function Main(input) {
	// 1行目がinput[0], 2行目がinput[1], …に入る
    input = input.split("\n");
    tmp1 = input[0].split(" ");
    N = parseInt(tmp1[0]);
    M = parseInt(tmp1[1]);
    var hairetu = [];
    for(i = 1; i < M +1; i++){
        i_nojyoho= input[i].split(" ")
        hairetu.push({kuni: parseInt(i_nojyoho[0]), shi: i, nen: parseInt(i_nojyoho[1])});
    }
    hairetu.sort(function(a,b){
        if(a.kuni < b.kuni) return -1;
        if(a.kuni > b.kuni) return 1;
        if(a.nen < b.nen) return -1;
        if(a.nen > b.nen) return 1;
        return 0;
    });
    for(i = 0; i < hairetu.length; i++){
        if(i === 0||hairetu[i].kuni !== hairetu[i-1].kuni){
            hairetu[i].jyun = 1;
        }else{
            hairetu[i].jyun = hairetu[i-1].jyun + 1;
        }
    }
    for(i = 0; i < hairetu.length; i++){
        bangou = length_plus(hairetu[i].kuni) + length_plus(hairetu[i].jyun);
        hairetu[i].bangou = bangou;
    }
    hairetu.sort(function(a,b){
        if(a.shi < b.shi) return -1;
        if(a.shi > b.shi) return 1;
        return 0;
    });
    for(i = 0; i < hairetu.length; i++){
        console.log(hairetu[i].bangou);
    }
}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));