Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N or cur_node <= 0 or cur_node >= N:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True
    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True

lst = []

for i in range(M):
    lst.append([0]*N)

for i in range(M):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1
    lst[idx2-1][idx1-1] = 1


graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0

    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N or cur_node <= 0 or cur_node >= N:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True
    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True

lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1
    lst[idx2-1][idx1-1] = 1


graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0

    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N or cur_node <= 0 or cur_node >= N:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True
    print(cur_node)
    print(pre_node)
    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True

lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1


graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0

    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N or cur_node <= 0 or cur_node >= N-1:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True

    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True
map[N-1] = True
lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1

graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0
    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N-1 or cur_node <= 0 or cur_node >= N-1:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True

    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True
map[N-1] = True
lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1

graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0
    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N-1 or cur_node <= 0 or cur_node >= N-1:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True

    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True
map[N-1] = True
lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1

graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0
    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N-1:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N or cur_node <= 0 or cur_node >= N-1:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True

    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True
map[N-1] = True
lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1

graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0
    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N-1:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N or cur_node <= 0 or cur_node >= N-1:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True

    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True

lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1

graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0
    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N-1:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

Buggy python submission (verdict: Runtime Error):
import copy
def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N or cur_node <= 0 or cur_node >= N:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True

    for i in range(N):
        if i != cur_node:
            dfs(i, cur_node, Node_num+1, map, l)


S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]


map = [False]*N
map[0] = True

lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1

graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0
    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N-1:
        graph_count = graph_count + 1

print(graph_count)



Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)

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

def dfs(cur_node, pre_node, Node_num, map, l):
    #全てのノードを見たとき

    if Node_num == N-1 or cur_node <= 0 or cur_node >= N:
        return
    elif l[pre_node][cur_node]==0: #飛んだ先が、Trueの時
        return
    elif map[cur_node]==True:
        return

    map[cur_node]=True

    dfs(cur_node+1, cur_node, Node_num+1, map, l)
    dfs(cur_node-1, cur_node, Node_num+1, map, l)



S = input()
S = list(map(int, S.split()))

N = S[0]
M = S[1]
map = [False]*N
map[0] = True

lst = []

for i in range(N):
    lst.append([0]*N)

for i in range(N):
    S = input()
    S = list(S.split())
    idx1 = int(S[0])
    idx2 = int(S[1])
    lst[idx1-1][idx2-1] = 1

graph_count = 0
#全探索
for i in range(1, N, 1):
    map_copy = copy.copy(map)
    lst_copy = copy.copy(lst)

    dfs(i, 0, 0, map_copy, lst_copy)
    count = 0
    for i in map_copy:
        if i == True:
            count = count + 1
    if count == N:
        graph_count = graph_count + 1

print(graph_count)


Fixed submission:
import itertools
N,M=map(int,input().split())
edges={tuple(sorted(map(int,input().split()))) for i in range(M)}
ans=0
for i in itertools.permutations(range(2,N+1),N-1):
    l=[1]+list(i)
    ans+=sum(1 for edge in zip(l,l[1:]) if tuple(sorted(edge)) in edges)==N-1
print(ans)