Buggy python submission (verdict: Time Limit Exceeded):
N, M = map(int, input().split())

# 隣接リストを作成
adjacencyList = [[] for _ in range(N)]

# 距離の情報
dp = [0] * N

# 入次数　（いりじすう）
deg = [0] * N

for _ in range(M):
    v, nv = map(int, input().split())
    adjacencyList[v-1].append(nv-1)
    #　入次数に1を足す
    deg[nv-1] += 1
    
queue = []

# BFS探索
# 入次数がゼロの頂点から探索を始める
for v in range(N):
    if deg[v] == 0:
        queue.append(v)

while queue:
    # 現在の頂点をqueueからpop
    v = queue.pop(0)
    for nv in adjacencyList[v]:
        # 探索済みの頂点の入次数を減らす
        deg[nv] -= 1
        
        # 完全に探索済みの頂点の入次数がゼロの時、経路の距離を出発点から計算
        if deg[nv] == 0:
            # 頂点をqueueに追加する
            queue.append(nv)
            dp[nv] = max(dp[v] + 1, dp[nv])
            
print(max(dp))

Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())

# 隣接リストを作成
adjacencyList = [[0] for i in range(N)]

# 距離の情報
dp = [0] * N

# 入次数　（いりじすう）
deg = [0] * N

for _ in range(M):
    v, nv = map(int, input().split())
    adjacencyList[v-1].append(nv-1)
    #　入次数に1を足す
    deg[nv-1] += 1
    
queue = []

# BFS探索
# 入次数がゼロの頂点から探索を始める
for v in range(N):
    if deg[v] == 0:
        queue.append(v)

while queue:
    # 現在の頂点をqueueからpop
    v = queue.pop(0)
    for nv in adjacencyList[cur]:
        # 探索済みの頂点の入次数を減らす
        deg[nv] -= 1
        
        # 完全に探索済みの頂点の入次数がゼロの時、経路の距離を出発点から計算
        if deg[nv] == 0:
            # 頂点をqueueに追加する
            queue.append(nv)
            dp[nv] = max(dp[v] + 1, dp[nv])
            
print(max(dp))

Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())

sys.setrecursionlimit(10**9)

vertices = [[] for i in range(N+1)]
dp = [-1] * (N+1)

for _ in range(M):
    fro, to = map(int, input().split())
    vertices[fro].append(to)

def dfs(i):
    
    if dp[i] != -1:
        return dp[i]
    
    temp = 0
    for vertex in vertices[i]:
        temp = max(temp, dfs(vertex)+1)
        
    dp[i] = temp
    return temp

for i in range(1,N+1):
    dfs(i)
    
print(max(dp))

Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())

sys.setrecursionlimit(10**9)

vertices = [[] for i in range(N+1)]
dp = [-1] * (N+1)

for _ in range(M):
    fro, to = map(int, input().split())
    vertices[fro].append(to)

def dfs(i):
    
    if dp[i] != -1:
        return dp[i]
    
    temp = 0
    for vertex in vertices[i]:
        temp = max(temp, dfs(vertex)+1)
        
    dp[i] = temp
    return temp

for i in range(1,N+1):
    dfs(i)
    
print(max(dp))


Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())

sys.setrecursionlimit(10**9)

vertices = [[] for i in range(N+1)]
dp = [-1] * (N+1)

for _ in range(M):
    fro, to = map(int, input().split())
    vertices[fro].append(to)

def dfs(i):
    
    if dp[i] != -1:
        return dp[i]
    
    temp = 0
    for vertex in vertices[i]:
        temp = max(temp, dfs(vertex)+1)
        
    dp[i] = temp
    return temp

for i in range(1,N+1):
    dfs(i)
    
print(max(dp))


Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())

sys.setrecursionlimit(10**9)

vertices = [[] for i in range(N+1)]
dp = [-1] * (N+1)

for _ in range(M):
    fro, to = map(int, input().split())
    vertices[fro].append(to)

def dfs(i):
    
    if dp[i] != -1:
        return dp[i]
    
    temp = 0
    for vertex in vertices[i]:
        temp = max(temp, dfs(vertex)+1)
        
    dp[i] = temp
    return temp

for i in range(1,N+1):
    dfs(i)
    
print(max(dp))

Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
import sys

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())

sys.setrecursionlimit(10**9)
 
vertices = [[] for i in range(N+1)]
dp = [-1] * (N+1)
 
for _ in range(M):
    fro, to = map(int, input().split())
    vertices[fro].append(to)

def dfs(i):
    
    if dp[i] != -1:
        return dp[i]
    
    temp = 0
    for vertex in vertices[i]:
        temp = max(temp, dfs(vertex)+1)
        
    dp[i] = temp
    return temp

for i in range(1,N+1):
    dfs(i)
    
print(max(dp))


Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)

Buggy python submission (verdict: Runtime Error):
N, M = map(int, input().split())

vertices = [[] for i in range(N+1)]
dp = [-1] * (N+1)

for _ in range(M):
    fro, to = map(int, input().split())
    vertices[fro].append(to)

def dfs(i):
    
    if dp[i] != -1:
        return dp[i]
    
    temp = 0
    for vertex in vertices[i]:
        temp = max(temp, dfs(vertex)+1)
        
    dp[i] = temp
    return temp

for i in range(1,N+1):
    dfs(i)
    
print(max(dp))

Fixed submission:
import sys

sys.setrecursionlimit(10**9)

n , m = map(int,input().split())

g = [[] for i in range(n+1)]

dp = [-1] * (n+1)
for _ in range(m):
    v1 , v2 = map(int,input().split())
    g[v1].append(v2)
    
# finding longest path for vertice i
def dfs(i):
    if dp[i]!=-1:
        return dp[i]
    temp = 0
    for nv in g[i]:
        temp = max(temp, dfs(nv)+1)

    dp[i]=temp
    return temp
  
# finding overall longest path  
res = 0  
for i in range(1,n+1):
    res = max(res, dfs(i))
print(res)