Buggy python submission (verdict: Runtime Error):
from collections import deque
n,m = map(int,input().split())
g = [[] for i in range(n)]
for i in range(m):
    x,y = map(int,input().split())
    g[x-1].append(y-1)
    g[y-1].append(x-1)
a = [-1]*n
d = deque([0])
while d:
    f = d.popleft()
    for o in g[f]:
        if a[o] == -1:
            a[o] = f
            d.append(o)
print("Yes")
for i in a[1:]:print(i+1)

Fixed submission:
import sys
from collections import defaultdict
dic1 = defaultdict(int)
dic2 = defaultdict(int)
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
mod = 10**9+7
def pow(n,p,mod=10**9+7): #繰り返し二乗法(nのp乗)
    res = 1
    while p > 0:
        if p % 2 == 0:
            n = n ** 2 % mod
            p //= 2
        else:
            res = res * n % mod
            p -= 1
    return res % mod
def gcd(a,b):
    if b == 0:
        return a
    else:
        return gcd(b,a%b)
def lcm(a,b):
    return (a//gcd(a,b)*b)
def to_standard_form(a, b):
    if a == 0:
        return (0, 1)
    g = gcd(a, b)
    a //= g
    b //= g
    if a < 0:
        return (-a, -b)
    return (a, b)
n = int(readline())
zero = 0
for i in range(n):
    a,b= map(int,readline().split())
    if a == b == 0:
        zero += 1
        continue
    plamai = 1 if a*b > 0 else 0
    a,b = to_standard_form(a,b)
    if b <= 0:
        dic2[(a,b)] += 1
    else:
        dic1[(b,-a)] += 1
        dic2[(b,-a)] += 0

ans = zero
k = 1
for key,cnt in dic2.items():
    cnt2 = dic1[key]
    x = pow(2,cnt)+pow(2,cnt2)
    k = k*(x-1)%mod
print((ans+k-1)%mod)

Buggy python submission (verdict: Runtime Error):
import sys
from collections import defaultdict
dic1 = defaultdict(int)
dic2 = defaultdict(int)
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
mod = 10**9+7
def pow(n,p,mod=10**9+7): #繰り返し二乗法(nのp乗)
    res = 1
    while p > 0:
        if p % 2 == 0:
            n = n ** 2 % mod
            p //= 2
        else:
            res = res * n % mod
            p -= 1
    return res % mod
def gcd(a,b):
    if b == 0:
        return a
    else:
        return gcd(b,a%b)
def lcm(a,b):
    return (a//gcd(a,b)*b)
def to_standard_form(a, b):
    if a == 0:
        return (0, 1)
    g = gcd(a, b)
    a //= g
    b //= g
    if a < 0:
        return (-a, -b)
    return (a, b)
n = int(readline())
zero = 0
for i in range(n):
    a,b= map(int,readline().split())
    if a == b == 0:
        zero += 1
        continue
    plamai = 1 if a*b > 0 else 0
    a,b = to_standard_form(a,b)
    if b <= 0:
        dic2[(a,b)] += 1
    else:
        dic1[(b,-a)] += 1
        dic2[(b,-a)] += 0

ans = zero
k = 1
for key,cnt in dic2.items():
    cnt2 = dic1[key]
    k = pow(2,cnt)+pow(2,cnt2)
    k = k*(x-1)%mod
print((ans+k-1)%mod)

Fixed submission:
import sys
from collections import defaultdict
dic1 = defaultdict(int)
dic2 = defaultdict(int)
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
mod = 10**9+7
def pow(n,p,mod=10**9+7): #繰り返し二乗法(nのp乗)
    res = 1
    while p > 0:
        if p % 2 == 0:
            n = n ** 2 % mod
            p //= 2
        else:
            res = res * n % mod
            p -= 1
    return res % mod
def gcd(a,b):
    if b == 0:
        return a
    else:
        return gcd(b,a%b)
def lcm(a,b):
    return (a//gcd(a,b)*b)
def to_standard_form(a, b):
    if a == 0:
        return (0, 1)
    g = gcd(a, b)
    a //= g
    b //= g
    if a < 0:
        return (-a, -b)
    return (a, b)
n = int(readline())
zero = 0
for i in range(n):
    a,b= map(int,readline().split())
    if a == b == 0:
        zero += 1
        continue
    plamai = 1 if a*b > 0 else 0
    a,b = to_standard_form(a,b)
    if b <= 0:
        dic2[(a,b)] += 1
    else:
        dic1[(b,-a)] += 1
        dic2[(b,-a)] += 0

ans = zero
k = 1
for key,cnt in dic2.items():
    cnt2 = dic1[key]
    x = pow(2,cnt)+pow(2,cnt2)
    k = k*(x-1)%mod
print((ans+k-1)%mod)

Buggy python submission (verdict: Runtime Error):
import sys
from collections import defaultdict
dic1 = defaultdict(int)
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
mod = 10**9+7
def pow(n,p,mod=10**9+7): #繰り返し二乗法(nのp乗)
    res = 1
    while p > 0:
        if p % 2 == 0:
            n = n ** 2 % mod
            p //= 2
        else:
            res = res * n % mod
            p -= 1
    return res % mod
def gcd(a,b):
    if b == 0:
        return a
    else:
        return gcd(b,a%b)
def lcm(a,b):
    return (a//gcd(a,b)*b)
n = int(readline())
#dic1
#[正負,比率1(小),比率2(大)]
for i in range(n):
    a,b= map(int,readline().split())
    plamai = 1 if a*b > 0 else 0
    if a < 0:a = -a
    if b < 0:b = -b
    res = gcd(a,b)
    if res == 0:
        zero += 1
        continue
    dic1[str(plamai)+" "+str(a//res)+" "+str(b//res)] += 1

ans = 1
dic2 = dict()
for i in dic1.keys():
    res = 0
    if not i in dic2:
        a = dic1[i]
        g,d,e = i.split()
        if g == "1":
            res2 = "0"+" "+e+" "+d
        else:
            res2 = "1"+" "+e+" "+d
        if res2 in dic1:
            b = dic1[res2]
        else:b = 0
        if a > 0:
            res += pow(2,a)
        if b > 0:
            res += pow(2,b)
        if a != 0 and b != 0:
            res -= 1
        ans *= res
        ans %= mod
        dic2[res2] = 1
if not zero:
    print(ans-1)
else:
    print(ans+pow(2,zero)-2)

Fixed submission:
import sys
from collections import defaultdict
dic1 = defaultdict(int)
dic2 = defaultdict(int)
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
mod = 10**9+7
def pow(n,p,mod=10**9+7): #繰り返し二乗法(nのp乗)
    res = 1
    while p > 0:
        if p % 2 == 0:
            n = n ** 2 % mod
            p //= 2
        else:
            res = res * n % mod
            p -= 1
    return res % mod
def gcd(a,b):
    if b == 0:
        return a
    else:
        return gcd(b,a%b)
def lcm(a,b):
    return (a//gcd(a,b)*b)
def to_standard_form(a, b):
    if a == 0:
        return (0, 1)
    g = gcd(a, b)
    a //= g
    b //= g
    if a < 0:
        return (-a, -b)
    return (a, b)
n = int(readline())
zero = 0
for i in range(n):
    a,b= map(int,readline().split())
    if a == b == 0:
        zero += 1
        continue
    plamai = 1 if a*b > 0 else 0
    a,b = to_standard_form(a,b)
    if b <= 0:
        dic2[(a,b)] += 1
    else:
        dic1[(b,-a)] += 1
        dic2[(b,-a)] += 0

ans = zero
k = 1
for key,cnt in dic2.items():
    cnt2 = dic1[key]
    x = pow(2,cnt)+pow(2,cnt2)
    k = k*(x-1)%mod
print((ans+k-1)%mod)

Buggy python submission (verdict: Runtime Error):
import sys
from collections import defaultdict
dic1 = defaultdict(int)
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
mod = 10**9+7
def pow(n,p,mod=10**9+7): #繰り返し二乗法(nのp乗)
    res = 1
    while p > 0:
        if p % 2 == 0:
            n = n ** 2 % mod
            p //= 2
        else:
            res = res * n % mod
            p -= 1
    return res % mod
def gcd(a,b):
    if b == 0:
        return a
    else:
        return gcd(b,a%b)
def lcm(a,b):
    return (a//gcd(a,b)*b)
n = int(readline())
#dic1
#[正負,比率1(小),比率2(大)]
for i in range(n):
    a,b= map(int,readline().split())
    plamai = 1 if a*b > 0 else 0
    if a < 0:a = -a
    if b < 0:b = -b
    res = gcd(a,b)
    
    dic1[str(plamai)+" "+str(a//res)+" "+str(b//res)] += 1

ans = 1
dic2 = dict()
for i in dic1.keys():
    res = 0
    if not i in dic2:
        a = dic1[i]
        g,d,e = i.split()
        if g == "1":
            res2 = "0"+" "+e+" "+d
        else:
            res2 = "1"+" "+e+" "+d
        if res2 in dic1:
            b = dic1[res2]
        else:b = 0
        if a > 0:
            res += pow(2,a)
        if b > 0:
            res += pow(2,b)
        if a != 0 and b != 0:
            res -= 1
        ans *= res
        ans %= mod
        dic2[res2] = 1

print(ans-1)

Fixed submission:
import sys
from collections import defaultdict
dic1 = defaultdict(int)
dic2 = defaultdict(int)
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
mod = 10**9+7
def pow(n,p,mod=10**9+7): #繰り返し二乗法(nのp乗)
    res = 1
    while p > 0:
        if p % 2 == 0:
            n = n ** 2 % mod
            p //= 2
        else:
            res = res * n % mod
            p -= 1
    return res % mod
def gcd(a,b):
    if b == 0:
        return a
    else:
        return gcd(b,a%b)
def lcm(a,b):
    return (a//gcd(a,b)*b)
def to_standard_form(a, b):
    if a == 0:
        return (0, 1)
    g = gcd(a, b)
    a //= g
    b //= g
    if a < 0:
        return (-a, -b)
    return (a, b)
n = int(readline())
zero = 0
for i in range(n):
    a,b= map(int,readline().split())
    if a == b == 0:
        zero += 1
        continue
    plamai = 1 if a*b > 0 else 0
    a,b = to_standard_form(a,b)
    if b <= 0:
        dic2[(a,b)] += 1
    else:
        dic1[(b,-a)] += 1
        dic2[(b,-a)] += 0

ans = zero
k = 1
for key,cnt in dic2.items():
    cnt2 = dic1[key]
    x = pow(2,cnt)+pow(2,cnt2)
    k = k*(x-1)%mod
print((ans+k-1)%mod)