Buggy python submission (verdict: Time Limit Exceeded):
n, m =  map(int, input().split())
py = [map(int, input().split()) for _ in range(m)]
p, y = [list(i) for i in zip(*py)]
pre = {}
for i in range(m):
    if p[i] not in pre.keys():
        pre[p[i]] = []
    pre[p[i]].append(y[i])
for i in pre.keys():
    pre[i].sort()
for i in range(m):
    num = str(p[i]*(10**6)+(pre[p[i]].index(y[i])+1)).zfill(12)
    print(num)

Fixed submission:
import sys
n,m = map(int, sys.stdin.readline().rstrip("\n").split())
city = {}
yton = {}
for i in range(m):
    p,y = map(int, sys.stdin.readline().rstrip("\n").split())
    if p not in city.keys():
        city[p] = []
        city[p].append(y)
        yton[y] = i
    else:
        city[p].append(y)
        yton[y] = i
ans = [None]*m
for p in city.keys():
    city[p].sort()
    for i,y in enumerate(city[p]):
        ans[yton[y]] = str(p*(10**6)+i+1).zfill(12)
print(*ans, sep = '\n')

Buggy python submission (verdict: Time Limit Exceeded):
n, m =  map(int, input().split())
py = [map(int, input().split()) for _ in range(m)]
p, y = [list(i) for i in zip(*py)]
pre = {}
for i in range(m):
    if p[i] not in pre.keys():
        pre[p[i]] = []
    pre[p[i]].append(y[i])
for i in pre.keys():
    pre[i].sort()
for i in range(m):
    print(str(p[i]*(10**6)+(pre[p[i]].index(y[i])+1)).zfill(12))

Fixed submission:
import sys
n,m = map(int, sys.stdin.readline().rstrip("\n").split())
city = {}
yton = {}
for i in range(m):
    p,y = map(int, sys.stdin.readline().rstrip("\n").split())
    if p not in city.keys():
        city[p] = []
        city[p].append(y)
        yton[y] = i
    else:
        city[p].append(y)
        yton[y] = i
ans = [None]*m
for p in city.keys():
    city[p].sort()
    for i,y in enumerate(city[p]):
        ans[yton[y]] = str(p*(10**6)+i+1).zfill(12)
print(*ans, sep = '\n')

Buggy python submission (verdict: Time Limit Exceeded):
n, m =  map(int, input().split())
py = [map(int, input().split()) for _ in range(m)]
p, y = [list(i) for i in zip(*py)]
pre = {}
for i in range(m):
    if p[i] not in pre.keys():
        pre[p[i]] = []
    pre[p[i]].append(y[i])
for i in pre.keys():
    pre[i].sort()
for i in range(m):
    num = str(p[i]*(10**6)+(pre[p[i]].index(y[i])+1))
    while len(num) < 12:
        num = '0' + num
    print(num)

Fixed submission:
import sys
n,m = map(int, sys.stdin.readline().rstrip("\n").split())
city = {}
yton = {}
for i in range(m):
    p,y = map(int, sys.stdin.readline().rstrip("\n").split())
    if p not in city.keys():
        city[p] = []
        city[p].append(y)
        yton[y] = i
    else:
        city[p].append(y)
        yton[y] = i
ans = [None]*m
for p in city.keys():
    city[p].sort()
    for i,y in enumerate(city[p]):
        ans[yton[y]] = str(p*(10**6)+i+1).zfill(12)
print(*ans, sep = '\n')

Buggy python submission (verdict: Time Limit Exceeded):
n, m =  map(int, input().split())
py = [map(int, input().split()) for _ in range(m)]
p, y = [list(i) for i in zip(*py)]
pre = {}
for i in range(m):
    if p[i] not in pre.keys():
        pre[p[i]] = []
    pre[p[i]].append(y[i])
for i in range(n):
    if i+1 in pre.keys():
        pre[i+1].sort()
for i in range(m):
    num = str(p[i]*(10**6)+(pre[p[i]].index(y[i])+1))
    while len(num) < 12:
        num = '0' + num
    print(num)

Fixed submission:
import sys
n,m = map(int, sys.stdin.readline().rstrip("\n").split())
city = {}
yton = {}
for i in range(m):
    p,y = map(int, sys.stdin.readline().rstrip("\n").split())
    if p not in city.keys():
        city[p] = []
        city[p].append(y)
        yton[y] = i
    else:
        city[p].append(y)
        yton[y] = i
ans = [None]*m
for p in city.keys():
    city[p].sort()
    for i,y in enumerate(city[p]):
        ans[yton[y]] = str(p*(10**6)+i+1).zfill(12)
print(*ans, sep = '\n')

Buggy python submission (verdict: Time Limit Exceeded):
n, m =  map(int, input().split())
plist=[]
ylist = []
n0list=[]
for i in range(m):
    p, y =  map(int, input().split())
    plist.append(p)
    ylist.append(y)
    n0list.append(1)
    for j in range(i):
        if p == plist[j]:
            if y > ylist[j]:
                n0list[i] = n0list[i]+1
            else:
                n0list[j] = n0list[j]+1
for i in range(m):
    num = str(plist[i]*(10**6)+n0list[i])
    while len(num) < 12:
        num = '0' + num
    print(num)

Fixed submission:
import sys
n,m = map(int, sys.stdin.readline().rstrip("\n").split())
city = {}
yton = {}
for i in range(m):
    p,y = map(int, sys.stdin.readline().rstrip("\n").split())
    if p not in city.keys():
        city[p] = []
        city[p].append(y)
        yton[y] = i
    else:
        city[p].append(y)
        yton[y] = i
ans = [None]*m
for p in city.keys():
    city[p].sort()
    for i,y in enumerate(city[p]):
        ans[yton[y]] = str(p*(10**6)+i+1).zfill(12)
print(*ans, sep = '\n')