Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
base = [[int(l) for l in input().split()] for i in range(M)]
sorted_target = sorted(base) 
  
prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[base.index(target)] = [prefecture_index, i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))

Fixed submission:
N, M = map(int, input().split())
base = []
for i in range(M):
  (a, b) = map(int, input().split())
  base.append((a, b, i))
sorted_target = sorted(base) 

prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[target[2]] = [prefecture_index, i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
base = [[int(l) for l in input().split()] for i in range(M)]
sorted_target = sorted(base) 
  
prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[base.index(target)] = [target[0], i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))

Fixed submission:
N, M = map(int, input().split())
base = []
for i in range(M):
  (a, b) = map(int, input().split())
  base.append((a, b, i))
sorted_target = sorted(base) 

prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[target[2]] = [prefecture_index, i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
base = [[int(l) for l in input().split()] for i in range(M)]
sort_target = sorted(base) 
  
prefecture_index = sort_target[0][0]
i=0
result = []
for target in sort_target:
  i = i + 1 if prefecture_index == target[0] else 1
  prefecture_index = target[0]
  result.append([base.index(target), target[0], i])

sorted_result = sorted(result) 
for result in sorted_result:
  print("{:0=6}{:0=6}".format(result[1], result[2]))

Fixed submission:
N, M = map(int, input().split())
base = []
for i in range(M):
  (a, b) = map(int, input().split())
  base.append((a, b, i))
sorted_target = sorted(base) 

prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[target[2]] = [prefecture_index, i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
base = [[int(l) for l in input().split()] for i in range(M)]
sort_target = sorted(base)
 
  
prefecture_index = sort_target[0][0]
i=0
result = []
for target in sort_target:
  i = i + 1 if prefecture_index == target[0] else 1
  prefecture_index = target[0]
  result.append([base.index(target), "{:0=6}{:0=6}".format(target[0], i)])
 
sorted_result = sorted(result) 
for result in sorted_result:
  print(result[1])

Fixed submission:
N, M = map(int, input().split())
base = []
for i in range(M):
  (a, b) = map(int, input().split())
  base.append((a, b, i))
sorted_target = sorted(base) 

prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[target[2]] = [prefecture_index, i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))

Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())
base = [[int(l) for l in input().split()] for i in range(M)]
sort_target = sorted(base)
 
  
prefecture_index = sort_target[0][0]
i=0
result = []
for target in sort_target:
  i = i + 1 if prefecture_index == target[0] else 1
  prefecture_index = target[0]
  result.append([base.index(target), "{:0=6}{:0=6}".format(target[0], i)])

sorted_result = sorted(result) 
for result in sorted_result:
  print(result[1])

Fixed submission:
N, M = map(int, input().split())
base = []
for i in range(M):
  (a, b) = map(int, input().split())
  base.append((a, b, i))
sorted_target = sorted(base) 

prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[target[2]] = [prefecture_index, i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))

Buggy python submission (verdict: Runtime Error):
import numpy as np
 
N, M = map(int, input().split())
base = [[int(l) for l in input().split()] for i in range(M)]
sort_target = np.sort(base, axis=0).tolist()
 
prefecture_index = sort_target[0][0]
i=0
result = []
for target in sort_target:
  i = i + 1 if prefecture_index == target[0] else 1
  prefecture_index = target[0]
  result.append([base.index(target), "{:0=6}{:0=6}".format(target[0], i)])
sorted_result = sorted(result)
 
for result in sorted_result:
  print(result[1])

Fixed submission:
N, M = map(int, input().split())
base = []
for i in range(M):
  (a, b) = map(int, input().split())
  base.append((a, b, i))
sorted_target = sorted(base) 

prefecture_index = sorted_target[0][0]

i=0
result = {}

for target in sorted_target:
  if prefecture_index == target[0]:
    i+=1
  else:
    prefecture_index = target[0]
    i = 1
  result[target[2]] = [prefecture_index, i]

for i in range(M):
  print("{:0=6}{:0=6}".format(result[i][0], result[i][1]))