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: Wrong Answer)

"use strict";function _slicedToArray(t,r){return _arrayWithHoles(t)||_iterableToArrayLimit(t,r)||_nonIterableRest()}function _nonIterableRest(){throw new TypeError("Invalid attempt to destructure non-iterable instance")}function _iterableToArrayLimit(t,r){var n=[],e=!0,i=!1,a=void 0;try{for(var o,l=t[Symbol.iterator]();!(e=(o=l.next()).done)&&(n.push(o.value),!r||n.length!==r);e=!0);}catch(t){i=!0,a=t}finally{try{e||null==l.return||l.return()}finally{if(i)throw a}}return n}function _arrayWithHoles(t){if(Array.isArray(t))return t}function Main(t){var r=t.split("\n"),n=r[0].split(" "),e=+n[0];n[1];r.shift();for(var i=r.map(function(t){var r=t.split(" ");return{pre:+r[0],year:+r[1]}}),a={},o=function(t){a[t.toString().padStart(6,"0")]=i.filter(function(r){return r.pre==t}).map(function(t){return t.year}).sort(function(t,r){return t-r})},l=1;l<=e;l++)o(l);Object.keys(a).forEach(function(t,r){var n=!0,e=!1,i=void 0;try{for(var o,l=a[t].entries()[Symbol.iterator]();!(n=(o=l.next()).done);n=!0){var u=_slicedToArray(o.value,2),f=u[0];u[1];console.log(t+(+f+1).toString().padStart(6,"0"))}}catch(t){e=!0,i=t}finally{try{n||null==l.return||l.return()}finally{if(e)throw i}}})}String.prototype.padStart||(String.prototype.padStart=function(t,r){return t>>=0,r=String(void 0!==r?r:" "),this.length>t?String(this):((t-=this.length)>r.length&&(r+=r.repeat(t/r.length)),r.slice(0,t)+String(this))}),Main(require("fs").readFileSync("/dev/stdin","utf8"));