C - ID

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 $2$, $...$).

2 3
1 32
2 63
1 12

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 $000001000001$.

2 3
2 55
2 77
2 99

000002000001
000002000002
000002000003