Buggy python submission (verdict: Runtime Error):
from heapq import*
(N,M),*t=[map(int,s.split())for s in open(0)]
z,*q=[0]*50*M
v=[[]for _ in q]
for a,b in t:v[a-1]+=b,
for i in v[:M]:z-=[heappush(q,-j)for j in i]or heappop(q)
print(z)

Fixed submission:
from collections import*
from heapq import*
n,m,*t=map(int,open(0).read().split())
d=defaultdict(list)
for a,b in zip(t[::2],t[1::2]):d[a].append(b)
q=[]
for i in sorted(d.keys())[::-1]:
    for b in sorted(d[i])[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        elif q and q[0]<b:heappushpop(q,b)
print(sum(q))

Buggy python submission (verdict: Runtime Error):
from heapq import*
(N,M),*t=[map(int,s.split())for s in open(0)]
z,*q=[0]*9*M
v=[[]for _ in q]
for a,b in t:v[a-1]+=b,
for i in v[:M]:
 for j in i:heappush(q,-j)
 z-=heappop(q)
print(z)

Fixed submission:
from collections import*
from heapq import*
n,m,*t=map(int,open(0).read().split())
d=defaultdict(list)
for a,b in zip(t[::2],t[1::2]):d[a].append(b)
q=[]
for i in sorted(d.keys())[::-1]:
    for b in sorted(d[i])[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        elif q and q[0]<b:heappushpop(q,b)
print(sum(q))

Buggy python submission (verdict: Time Limit Exceeded):
from heapq import*
(N,M),*t=[map(int,s.split())for s in open(0)]
z,*q=[0]*99*M
v=[[]for _ in q]
for a,b in t:v[a-1]+=b,
for i in v[:M]:
 for j in i:heappush(q,-j)
 z-=heappop(q)
print(z)

Fixed submission:
from collections import*
from heapq import*
n,m,*t=map(int,open(0).read().split())
d=defaultdict(list)
for a,b in zip(t[::2],t[1::2]):d[a].append(b)
q=[]
for i in sorted(d.keys())[::-1]:
    for b in sorted(d[i])[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        elif q and q[0]<b:heappushpop(q,b)
print(sum(q))

Buggy python submission (verdict: Runtime Error):
from heapq import*
(N,M),*t=[map(int,s.split())for s in open(0)]
q=[0]*M
v=[[]for _ in q]
z=0
for a,b in t:v[a-1]+=[b]*(a<=M)
for i in v:
	for j in i:heappush(q,-j)
	z-=heappop(q)
print(z)

Fixed submission:
from collections import*
from heapq import*
n,m,*t=map(int,open(0).read().split())
d=defaultdict(list)
for a,b in zip(t[::2],t[1::2]):d[a].append(b)
q=[]
for i in sorted(d.keys())[::-1]:
    for b in sorted(d[i])[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        elif q and q[0]<b:heappushpop(q,b)
print(sum(q))

Buggy python submission (verdict: Runtime Error):
from collections import*
from heapq import*
n,m,*t=map(int,open(0).read().split())
d=defaultdict(list)
for a,b in zip(t[::2],t[1::2]):d[a].append(b)
q=[]
for i in sorted(d.keys())[::-1]:
    for b in sorted(d[i])[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        else:
            if q[0]<b:heappushpop(q,b)
print(sum(q))

Fixed submission:
from collections import*
from heapq import*
n,m,*t=map(int,open(0).read().split())
d=defaultdict(list)
for a,b in zip(t[::2],t[1::2]):d[a].append(b)
q=[]
for i in sorted(d.keys())[::-1]:
    for b in sorted(d[i])[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        elif q and q[0]<b:heappushpop(q,b)
print(sum(q))

Buggy python submission (verdict: Runtime Error):
from heapq import*
n,m,*t=map(int,open(0).read().split())
k=max(t)
d=[[]for _ in range(k+1)]
for a,b in zip(t[::2],t[1::2]):d[a]+=b,
q=[]
for i,b in enumerate(d[::-1]):
    i=k-i
    for b in sorted(b)[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        else:
            if q[0]<b:heappushpop(q,b)
print(sum(q))

Fixed submission:
from collections import*
from heapq import*
n,m,*t=map(int,open(0).read().split())
d=defaultdict(list)
for a,b in zip(t[::2],t[1::2]):d[a].append(b)
q=[]
for i in sorted(d.keys())[::-1]:
    for b in sorted(d[i])[::-1][:m-i+1]:
        if len(q)<=m-i:heappush(q,b)
        elif q and q[0]<b:heappushpop(q,b)
print(sum(q))