Buggy python submission (verdict: Time Limit Exceeded):
N,M=map(int,input().split())
from collections import defaultdict,deque
branch=defaultdict(dict)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a-1][b-1]=c
inf=10**15
dist=[(-inf,set())]*N
dist[0]=(0,{0})
check={0}
while len(check)>0:
    now=check.pop()
    for nex,s in branch[now].items():
        if nex not in dist[now][1]:
            dist[nex]=(dist[now][0]+s,dist[now][1]|{nex})
            check|={nex}
        elif dist[now][0]>=inf:
            continue
        elif dist[now][0]+s>dist[nex][0]:
            dist[nex]=(inf,{nex})
            check|={nex}
if dist[N-1][0]>=inf:
    print('inf')
else:
    print(dist[N-1][0])

Fixed submission:
N,M=map(int,input().split())
big=10**13
data=[-1*float('inf')]*(N+1)
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
from collections import deque
check=deque()
check.append((1,0,set()))
data[1]=0
while len(check)>0:
    now=check.popleft()
    for b,c in branch[now[0]]:
        if now[1]+c>data[b]:
            if data[b]>big:continue
            if b in now[2]:
                data[b]=float('inf')
                check.append((now[0],float('inf'),now[2]|{now[0],b}))
                check.append((b,float('inf'),now[2]|{now[0],b}))
            else:
                data[b]=now[1]+c
                check.append((b,now[1]+c,now[2]|{now[0],}))
if data[N]>big:print('inf')
else:print(data[N])

Buggy python submission (verdict: Time Limit Exceeded):
N,M=map(int,input().split())
from collections import defaultdict,deque
branch=defaultdict(dict)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a-1][b-1]=c
check=deque([({0:0},[0])])
inf=10**15
ans=-inf
while len(check)>0:
    scores,visited=check.popleft()
    now=visited[-1]
    for nex,s in branch[now].items():
        if nex==N-1:
            ans=max(ans,scores[now]+s)
        if nex not in visited:
            scores[nex]=scores[now]+s
            check.append((scores,visited+[nex]))
        elif scores[now]>=inf:
            continue
        elif scores[now]+s>scores[nex]:
            scores[nex]=inf
            check.append((scores,[nex]))
if ans>=inf:
    print('inf')
else:
    print(ans)

Fixed submission:
N,M=map(int,input().split())
big=10**13
data=[-1*float('inf')]*(N+1)
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
from collections import deque
check=deque()
check.append((1,0,set()))
data[1]=0
while len(check)>0:
    now=check.popleft()
    for b,c in branch[now[0]]:
        if now[1]+c>data[b]:
            if data[b]>big:continue
            if b in now[2]:
                data[b]=float('inf')
                check.append((now[0],float('inf'),now[2]|{now[0],b}))
                check.append((b,float('inf'),now[2]|{now[0],b}))
            else:
                data[b]=now[1]+c
                check.append((b,now[1]+c,now[2]|{now[0],}))
if data[N]>big:print('inf')
else:print(data[N])

Buggy python submission (verdict: Runtime Error):
N,M=map(int,input().split())
big=10**13
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
def dps(now,score,visited,ans):
    if now==N:
        ans=max(score,ans)
    for b,c in branch[now]:
        if ans>big:return ans
        if  b in visited:
            if score>big:continue
            else:ans=dps(a,float('inf'),visited,ans)
        else:
            ans=dps(b,score+c,visited|{now,},ans)
    return ans
ans=dps(1,0,set(),-1*float('inf'))
if ans>big:print('inf')
else:print(ans)

Fixed submission:
N,M=map(int,input().split())
big=10**13
data=[-1*float('inf')]*(N+1)
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
from collections import deque
check=deque()
check.append((1,0,set()))
data[1]=0
while len(check)>0:
    now=check.popleft()
    for b,c in branch[now[0]]:
        if now[1]+c>data[b]:
            if data[b]>big:continue
            if b in now[2]:
                data[b]=float('inf')
                check.append((now[0],float('inf'),now[2]|{now[0],b}))
                check.append((b,float('inf'),now[2]|{now[0],b}))
            else:
                data[b]=now[1]+c
                check.append((b,now[1]+c,now[2]|{now[0],}))
if data[N]>big:print('inf')
else:print(data[N])

Buggy python submission (verdict: Runtime Error):
N,M=map(int,input().split())
big=10**13
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
def dps(now,score,visited,ans):
    if now==N:
        ans=max(score,ans)
    if len(branch[now])==0:
        return ans
    for b,c in branch[now]:
        if ans>big:return ans
        if  b in visited:
            return float('inf')
        ans=dps(b,score+c,visited|{now,},ans)
    return ans
ans=dps(1,0,set(),-1*float('inf'))
if ans>big:print('inf')
else:print(ans)

Fixed submission:
N,M=map(int,input().split())
big=10**13
data=[-1*float('inf')]*(N+1)
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
from collections import deque
check=deque()
check.append((1,0,set()))
data[1]=0
while len(check)>0:
    now=check.popleft()
    for b,c in branch[now[0]]:
        if now[1]+c>data[b]:
            if data[b]>big:continue
            if b in now[2]:
                data[b]=float('inf')
                check.append((now[0],float('inf'),now[2]|{now[0],b}))
                check.append((b,float('inf'),now[2]|{now[0],b}))
            else:
                data[b]=now[1]+c
                check.append((b,now[1]+c,now[2]|{now[0],}))
if data[N]>big:print('inf')
else:print(data[N])

Buggy python submission (verdict: Runtime Error):
N,M=map(int,input().split())
big=10**13
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
def dps(now,score,visited,ans):
    if now==N:
        ans=max(score,ans)
    if len(branch[now])==0:
        return ans
    for b,c in branch[now]:
        if ans>big:return ans
        if  b in visited:
            return float('inf')
        ans=dps(b,score+c,visited|{now,},ans)
    return ans
print(dps(1,0,set(),-1*float('inf')))

Fixed submission:
N,M=map(int,input().split())
big=10**13
data=[-1*float('inf')]*(N+1)
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
from collections import deque
check=deque()
check.append((1,0,set()))
data[1]=0
while len(check)>0:
    now=check.popleft()
    for b,c in branch[now[0]]:
        if now[1]+c>data[b]:
            if data[b]>big:continue
            if b in now[2]:
                data[b]=float('inf')
                check.append((now[0],float('inf'),now[2]|{now[0],b}))
                check.append((b,float('inf'),now[2]|{now[0],b}))
            else:
                data[b]=now[1]+c
                check.append((b,now[1]+c,now[2]|{now[0],}))
if data[N]>big:print('inf')
else:print(data[N])

Buggy python submission (verdict: Runtime Error):
N,M=map(int,input().split())
big=10**13
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
def dps(now,score,visited,ans):
    if now==N:
        ans=max(score,ans)
    for b,c in branch[now]:
        if ans>big:return ans
        if  b in visited:
            return float('inf')
        ans=dps(b,score+c,visited|{now,},ans)
    return ans
print(dps(1,0,set(),-1*float('inf')))

Fixed submission:
N,M=map(int,input().split())
big=10**13
data=[-1*float('inf')]*(N+1)
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
from collections import deque
check=deque()
check.append((1,0,set()))
data[1]=0
while len(check)>0:
    now=check.popleft()
    for b,c in branch[now[0]]:
        if now[1]+c>data[b]:
            if data[b]>big:continue
            if b in now[2]:
                data[b]=float('inf')
                check.append((now[0],float('inf'),now[2]|{now[0],b}))
                check.append((b,float('inf'),now[2]|{now[0],b}))
            else:
                data[b]=now[1]+c
                check.append((b,now[1]+c,now[2]|{now[0],}))
if data[N]>big:print('inf')
else:print(data[N])

Buggy python submission (verdict: Runtime Error):
N,M=map(int,input().split())
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
def dps(now,score,visited,ans):
    if now==N:
        ans=max(score,ans)
    for b,c in branch[now]:
        if  b in visited:
            return 'inf'
        ans=dps(b,score+c,visited|{now,},ans)
    return ans
print(dps(1,0,set(),-1*float('inf')))

Fixed submission:
N,M=map(int,input().split())
big=10**13
data=[-1*float('inf')]*(N+1)
from collections import defaultdict
branch=defaultdict(set)
for i in range(M):
    a,b,c=map(int,input().split())
    branch[a]|={(b,c),}
from collections import deque
check=deque()
check.append((1,0,set()))
data[1]=0
while len(check)>0:
    now=check.popleft()
    for b,c in branch[now[0]]:
        if now[1]+c>data[b]:
            if data[b]>big:continue
            if b in now[2]:
                data[b]=float('inf')
                check.append((now[0],float('inf'),now[2]|{now[0],b}))
                check.append((b,float('inf'),now[2]|{now[0],b}))
            else:
                data[b]=now[1]+c
                check.append((b,now[1]+c,now[2]|{now[0],}))
if data[N]>big:print('inf')
else:print(data[N])