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 Fortran (gfortran v4.8.4) (judge verdict: Accepted)

integer(16)::n,m,i,j,q,r
integer(16),allocatable::p(:),y(:),a(:),b(:),c(:)
read*,n,m
allocate(p(m),y(m),a(m))
do i = 1,m
  read*,p(i),y(i)
  a(i) = i
end do
	
call HeapsortTri(M,p,a,y)
q = 1;r = 1
do
  do 
    if(r+1 > m)exit
    if(p(r+1)/=p(r))exit
	r = r+1
  end do
  j = r-q+1
  allocate(b(j),c(j))
  b(1:j) = y(q:r)
  c(1:j) = a(q:r)
  
  call HeapsortPair(J,b,c)
  
  do i = 1,j
    b(i) = i
  enddo
  y(q:r) = b(1:j)
  a(q:r) = c(1:j)
  q = r+1
  r = r+1
  deallocate(b,c)
  if(r>m)exit
end do
	
call heapsorttri(m,a,p,y)
	
do i = 1,m
  print"(i12.12)",p(i)*1000000+y(i)
end do

contains
subroutine HeapsortTri(n,array,array2,array3)
  implicit none
!ここの入力は状況に応じて変更すること
  integer(16),intent(in) :: n
  integer(16),intent(inout) :: array(1:n),array2(1:n),array3(1:N)
  integer(16)::i,k,j,l
  integer(16):: t,t2,t3

  l=n/2+1
  k=n
  do while(k /= 1)
     if(l > 1)then
        l=l-1
        t=array(L)
        t2=array2(L)
        t3=array3(L)
     else
        t=array(k)
        t2=array2(k)
        t3=array3(k)
        array(k)=array(1)
        array2(k)=array2(1)
        array3(k)=array3(1)
        k=k-1
        if(k == 1) then
           array(1)=t
           array2(1)=t2
           array3(1)=t3
           exit
        endif
     endif
     i=l
     j=l+l
     do while(j<=k)
        if(j < k)then
           if(array(j) < array(j+1))j=j+1
        endif
        if (t < array(j))then
           array(i)=array(j)
           array2(i)=array2(j)
           array3(i)=array3(j)
           i=j
           j=j+j
        else
           j=k+1
        endif
     enddo
     array(i)=t
     array2(i)=t2
     array3(i)=t3
  enddo
  return
end subroutine HeapsortTri


subroutine HeapsortPair(n,array,array2)
  implicit none
!ここの入力は状況に応じて変更すること
  integer(16),intent(in) :: n
  integer(16),intent(inout) :: array(1:n),array2(1:n)
  integer(16)::i,k,j,l
  integer(16):: t,t2

  l=n/2+1
  k=n
  do while(k /= 1)
     if(l > 1)then
        l=l-1
        t=array(L)
        t2=array2(L)
     else
        t=array(k)
        t2=array2(k)
        array(k)=array(1)
        array2(k)=array2(1)
        k=k-1
        if(k == 1) then
           array(1)=t
           array2(1)=t2
           exit
        endif
     endif
     i=l
     j=l+l
     do while(j<=k)
        if(j < k)then
           if(array(j) < array(j+1))j=j+1
        endif
        if (t < array(j))then
           array(i)=array(j)
           array2(i)=array2(j)
           i=j
           j=j+j
        else
           j=k+1
        endif
     enddo
     array(i)=t
     array2(i)=t2
  enddo
  return
end subroutine HeapsortPair
end