Buggy python submission (verdict: Runtime Error):
### 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())

    # グラフgを初期化
    g = [[] for _ in range(N)]

    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)

    return N, M, g


def getlp(x, depth):
    global dp, g

    if depth >= MAX_DEPTH:
        return -1
    elif dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y, depth + 1)
            if yp == -1:
                return -1
            elif yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
        return dp[x]


N, M, g = get_inputs()
MAX_DEPTH = 999

dp = [-1] * N
nodes = list(range(N))
ans = 0

while len(nodes) > 0:
    tmp_nodes = []
    for x in range(N):
        if dp[x] == -1:
            t = getlp(x, 0)
            if t == -1:
                tmp_nodes.append(x)
            else:
                ans = max(ans, t)
        else:
            ans = max(ans, dp[x])

    nodes = list(tmp_nodes)

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
### 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())

    # グラフgを初期化
    g = [[] for _ in range(N)]

    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)

    return N, M, g


def getlp(x, depth):
    global dp, g

    if depth >= MAX_DEPTH:
        return -1
    elif dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y, depth + 1)
            if yp == -1:
                return -1
            elif yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
        return dp[x]


N, M, g = get_inputs()
MAX_DEPTH = 900

dp = [-1] * N
nodes = list(range(N))
ans = 0

while len(nodes) > 0:
    tmp_nodes = []
    for x in range(N):
        if dp[x] == -1:
            t = getlp(x, 0)
            if t == -1:
                tmp_nodes.append(x)
            else:
                ans = max(ans, t)
        else:
            ans = max(ans, dp[x])

    nodes = list(tmp_nodes)

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
### 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())

    # グラフgを初期化
    g = [[] for _ in range(N)]

    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)

    return N, M, g


def getlp(x, depth):
    global dp, g

    if depth >= MAX_DEPTH:
        return -1
    elif dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y, depth + 1)
            if yp == -1:
                return -1
            elif yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
        return dp[x]


N, M, g = get_inputs()
MAX_DEPTH = 800

dp = [-1] * N
nodes = list(range(N))
ans = 0

while len(nodes) > 0:
    tmp_nodes = []
    for x in range(N):
        if dp[x] == -1:
            t = getlp(x, 0)
            if t == -1:
                tmp_nodes.append(x)
            else:
                ans = max(ans, t)
        else:
            ans = max(ans, dp[x])

    nodes = list(tmp_nodes)

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
### 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())

    # グラフgを初期化
    g = [[] for _ in range(N)]

    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)

    return N, M, g


def getlp(x, depth):
    global dp, g

    if depth >= MAX_DEPTH:
        return -1
    elif dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y, depth + 1)
            if yp == -1:
                return -1
            elif yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
        return dp[x]


N, M, g = get_inputs()
MAX_DEPTH = 500

dp = [-1] * N
nodes = list(range(N))
ans = 0

while len(nodes) > 0:
    tmp_nodes = []
    for x in range(N):
        if dp[x] == -1:
            t = getlp(x, 0)
            if t == -1:
                tmp_nodes.append(x)
            else:
                ans = max(ans, t)
        else:
            ans = max(ans, dp[x])

    nodes = list(tmp_nodes)

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
### 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())

    # グラフgを初期化
    g = [[] for _ in range(N)]

    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)

    return N, M, g


def getlp(x, depth):
    global dp, g

    if depth >= MAX_DEPTH:
        return -1
    elif dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y, depth + 1)
            if yp == -1:
                return -1
            elif yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
        return dp[x]


N, M, g = get_inputs()
MAX_DEPTH = 1000

dp = [-1] * N
nodes = list(range(N))
ans = 0

while len(nodes) > 0:
    tmp_nodes = []
    for x in range(N):
        if dp[x] == -1:
            t = getlp(x, 0)
            if t == -1:
                tmp_nodes.append(x)
            else:
                ans = max(ans, t)
        else:
            ans = max(ans, dp[x])

    nodes = list(tmp_nodes)

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
### 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y)
            if yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N-1, -1, -1):
    ans = max(ans, getlp(x))

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
# 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y)
            if yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
# 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())

    # グラフgを初期化
    g = [[] for _ in range(N)]

    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, (input().split()))
        g[x].append(y)

    return N, M, g


def getlp(x):
    global dp, g

    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y)
            if yp > mxp:
                mxp = yp
        dp[x] = mxp + 1

    return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
# 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ

def get_inputs():
    N, M = map(int, input().split())

    # グラフgを初期化
    g = [[] for _ in range(N)]

    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, (input().split()))
        g[x].append(y)

    return N, M, g


def getlp(x):
    global dp, g

    if dp[x] != -1:
        pass
    elif len(g[x]) == 0:
        dp[x] = 0
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y)
            if yp > mxp:
                mxp = yp
        dp[x] = mxp + 1

    return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    dp[x] = getlp(x)
    ans = max(ans, dp[x])

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
# 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ
dp = [-1] * N

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, (input().split()))
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        pass
    elif len(g[x]) == 0:
        dp[x] = 0
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y)
            if yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
    
    return dp[x]


N, M, g = get_inputs()

ans = 0
for x in range(N):
    dp[x] = getlp(x)
    ans = max(ans, dp[x])

print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
# 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ
dp = [-1] * N

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, (input().split()))
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        pass
    elif len(g[x]) == 0:
        dp[x] = 0
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y)
            if yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
    
    return dp[x]


if __name__ == "__main__":
    N, M, g = get_inputs()
    
    ans = 0
    for x in range(N):
        dp[x] = getlp(x)
        ans = max(ans, dp[x])
    
    print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)

Buggy python submission (verdict: Runtime Error):
# 動的計画法のテーブルを用意
# dp(n) は頂点nを始点として時の最大有効パスの長さ
dp = [-1] * N

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, (input().split()))
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        pass
    elif len(g[x]) == 0:
        dp[x] = 0
    else:
        mxp = 0
        for y in g[x]:
            yp = getlp(y)
            if yp > mxp:
                mxp = yp
        dp[x] = mxp + 1
    
    return dp[x]


if __name__ == "__main__":
    N, M, g = get_inputs()
    
    ans = 0
    for x in range(N):
        dp[x] = getlp(x)
        ans = max(ans, dp[x])
    
    print(ans)


Fixed submission:
import sys
sys.setrecursionlimit(10**5)

def get_inputs():
    N, M = map(int, input().split())
    
    # グラフgを初期化
    g = [[] for _ in range(N)]
    
    # 辺情報を読み込みgに追加
    for _ in range(M):
        x, y = map(lambda c: int(c) - 1, input().split())
        g[x].append(y)
    
    return N, M, g


def getlp(x):
    global dp, g
    
    if dp[x] != -1:
        return dp[x]
    elif len(g[x]) == 0:
        dp[x] = 0
        return dp[x]
    else:
        dp[x] = max([getlp(y) for y in g[x]]) + 1
        return dp[x]


N, M, g = get_inputs()

dp = [-1] * N
ans = 0
for x in range(N):
    ans = max(ans, getlp(x))

print(ans)