Buggy python submission (verdict: Time Limit Exceeded):
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())

    E = {}
    for i in range(0, N+1):
    E[i] = []
    for i in range(N-1):
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
    dp[c][0], dp[c][1] = 1, 1
    for to in E[c]:
        if to != p:
            dfs(to, c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
   N = int(input())

    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]


    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]


    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
import sys
sys.setrecursionlimit(1000000)
MOD = 10**9+7
E = {}
for i in range(0,N+1):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]


dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
import sys
sys.setrecursionlimit(1000000000)
MOD = 10**9+7
E = {}
for i in range(0,N+1):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]


dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
import sys
sys.setrecursionlimit(1000000)
MOD = 10**9+7
E = {}
for i in range(0,N+1):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= (dp[to][0] + dp[to][1])%MOD
            dp[c][1] *= (dp[to][0])%MOD

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
import sys
sys.setrecursionlimit(1000000)
MOD = 10**9+7
E = {}
for i in range(0,N+1):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
import sys
sys.setrecursionlimit(10000000)
MOD = 10**9+7
E = {}
for i in range(0,N):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]
            dp[c][0] %= MOD
            dp[c][1] %= MOD

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
import sys
sys.setrecursionlimit(1000000)
MOD = 10**9+7
E = {}
for i in range(0,N):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]
            dp[c][0] %= MOD
            dp[c][1] %= MOD

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
import sys
sys.setrecursionlimit(1000000)
MOD = 10**9+7
E = {}
for i in range(0,N+1):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(1000100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]
            dp[c][0] %= MOD
            dp[c][1] %= MOD

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
N = int(input())
MOD = 10**9+7
E = {}
for i in range(0,N+1):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(1000100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]
            dp[c][0] %= MOD
            dp[c][1] %= MOD

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
N = int(input())
MOD = 10**9+7
E = {}
for i in range(0,N+1):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]
            dp[c][0] %= MOD
            dp[c][1] %= MOD

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
N = int(input())
MOD = 10**9+7
E = {}
for i in range(0,N):
    E[i] = []
for i in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    E[a].append(b)
    E[b].append(a)

dp = [ [0 for i in range(2)] for j in range(100100)]

def dfs(c,p):
    dp[c][0],dp[c][1] = 1,1
    for to in E[c]:
        if to != p:
            dfs(to,c)
            dp[c][0] *= dp[to][0] + dp[to][1]
            dp[c][1] *= dp[to][0]

dfs(0,-1)

ans = (dp[0][0] + dp[0][1]) % MOD
print(ans)


Fixed submission:
from heapq import heappush, heappop
import collections
import math
import heapq
from collections import defaultdict
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7
inf = float("inf")


def main():
    N = int(input())
    E = {}
    for i in range(0, N+1):
        E[i] = []
    for i in range(N-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        E[a].append(b)
        E[b].append(a)

    dp = [[0 for i in range(2)] for j in range(100100)]

    def dfs(c, p):
        dp[c][0], dp[c][1] = 1, 1
        for to in E[c]:
            if to != p:
                dfs(to, c)
                dp[c][0] *= dp[to][0] + dp[to][1]
                dp[c][1] *= dp[to][0]

    dfs(0, -1)

    ans = (dp[0][0] + dp[0][1]) % MOD
    print(ans)


if __name__ == '__main__':
    main()