The numbers 1,   2,   ...,   n ⋅ k are colored with n colors. These colors are indexed by 1,   2,   ...,   n. For each 1 ≤ i ≤ n, there are exactly k numbers colored with color i.

Let [a,   b] denote the interval of integers between a and b inclusive, that is, the set \\{a,   a + 1,   ...,   b\}. You must choose n intervals [a_1,   b_1],   [a_2,   b_2],   ..., [a_n,   b_n] such that: 

  * for each 1 ≤ i ≤ n, it holds 1 ≤ a_i < b_i ≤ n ⋅ k; 
  * for each 1 ≤ i ≤ n, the numbers a_i and b_i are colored with color i; 
  * each number 1 ≤ x ≤ n ⋅ k belongs to at most \left⌈ (n)/(k - 1) \right⌉ intervals. 



One can show that such a family of intervals always exists under the given constraints.

Input

The first line contains two integers n and k (1 ≤ n ≤ 100, 2 ≤ k ≤ 100) — the number of colors and the number of occurrences of each color.

The second line contains n ⋅ k integers c_1,   c_2,   ...,   c_{nk} (1 ≤ c_j ≤ n), where c_j is the color of number j. It is guaranteed that, for each 1 ≤ i ≤ n, it holds c_j = i for exactly k distinct indices j.

Output

Output n lines. The i-th line should contain the two integers a_i and b_i.

If there are multiple valid choices of the intervals, output any.

Examples

Input


4 3
2 4 3 1 1 4 2 3 2 1 3 4


Output


4 5
1 7
8 11
6 12

Input


1 2
1 1


Output


1 2


Input


3 3
3 1 2 3 2 1 2 1 3


Output


6 8
3 7
1 4

Input


2 3
2 1 1 1 2 2


Output


2 3
5 6

Note

In the first sample, each number can be contained in at most \left⌈ (4)/(3 - 1) \right⌉ = 2 intervals. The output is described by the following picture:

<image>

In the second sample, the only interval to be chosen is forced to be [1,   2], and each number is indeed contained in at most \left⌈ (1)/(2 - 1) \right⌉ = 1 interval.

In the third sample, each number can be contained in at most \left⌈ (3)/(3 - 1) \right⌉ = 2 intervals. The output is described by the following picture:

<image>
import sys
input = sys.stdin.readline
from operator import itemgetter

n,k=map(int,input().split())
C=list(map(int,input().split()))

CLIST=[[] for i in range(n)]

for i in range(n*k):
    CLIST[C[i]-1].append(i)

SUM=[0]*(n*k)


MAX=(n+(k-2))//(k-1)

C2=[]
for i in range(n):
    for j in range(len(CLIST[i])-1):
        x,y=CLIST[i][j],CLIST[i][j+1]
        C2.append((x,y,i))

C2.sort(key=itemgetter(1))

seg_el=1<<((n*k+5).bit_length())
SEG=[0]*(2*seg_el)
LAZY=[0]*(2*seg_el)

def indexes(L,R):
    INDLIST=[]

    R-=1
    
    L>>=1
    R>>=1

    while L!=R:
        if L>R:
            INDLIST.append(L)
            L>>=1
        else:
            INDLIST.append(R)
            R>>=1

    while L!=0:
        INDLIST.append(L)
        L>>=1

    return INDLIST
        

def adds(l,r,x):
        
    L=l+seg_el
    R=r+seg_el

    L//=(L & (-L))
    R//=(R & (-R))

    UPIND=indexes(L,R)
    
    for ind in UPIND[::-1]:
        if LAZY[ind]!=0:
            plus_lazy=LAZY[ind]
            
            SEG[ind<<1]+=plus_lazy
            SEG[1+(ind<<1)]+=plus_lazy
            
            LAZY[ind<<1]+=plus_lazy
            LAZY[1+(ind<<1)]+=plus_lazy
            
            LAZY[ind]=0
    
    while L!=R:
        if L > R:
            SEG[L]+=x
            LAZY[L]+=x
            L+=1
            L//=(L & (-L))

        else:
            R-=1
            SEG[R]+=x
            LAZY[R]+=x
            R//=(R & (-R))

    for ind in UPIND:
        SEG[ind]=max(SEG[ind<<1],SEG[1+(ind<<1)])
        
def getvalues(l,r):

    L=l+seg_el
    R=r+seg_el

    L//=(L & (-L))
    R//=(R & (-R))

    UPIND=indexes(L,R)
    
    for ind in UPIND[::-1]:
        if LAZY[ind]!=0:
            plus_lazy=LAZY[ind]
            
            SEG[ind<<1]+=plus_lazy
            SEG[1+(ind<<1)]+=plus_lazy
            
            LAZY[ind<<1]+=plus_lazy
            LAZY[1+(ind<<1)]+=plus_lazy
            
            LAZY[ind]=0
            
    ANS=0

    while L!=R:
        if L > R:
            ANS=max(ANS , SEG[L])
            L+=1
            L//=(L & (-L))

        else:
            R-=1
            ANS=max(ANS , SEG[R])
            R//=(R & (-R))

    return ANS

ANS=[[-1,-1] for i in range(n)]

for x,y,ind in C2:
    if ANS[ind]!=[-1,-1]:
        continue

    if getvalues(x,y)>=MAX:
        continue

    ANS[ind]=[x,y]
    adds(x,y+1,1)

for x,y in ANS:
    print(x+1,y+1)
    

    


