Problem p03410 (python)

Fixed submission:
#!usr/bin/env python3
from collections import defaultdict
from collections import deque
from heapq import heappush, heappop
import sys
import math
import bisect
import random
def LI(): return list(map(int, sys.stdin.readline().split()))
def I(): return int(sys.stdin.readline())
def LS():return list(map(list, sys.stdin.readline().split()))
def S(): return list(sys.stdin.readline())[:-1]
def IR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = I()
    return l
def LIR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = LI()
    return l
def SR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = S()
    return l
def LSR(n):
    l = [None for i in range(n)]
    for i in range(n):l[i] = SR()
    return l
mod = 1000000007

#A
def A():
    return

#B
def B():
    return

#C
def C():
    def bfs(a,b):
        bfs_map = [-1 for i in range(2*n+2)]
        q = [a]
        bfs_map[a] = 0
        while q:
            x = q.pop(0)
            for y in out[x]:
                if bfs_map[y] == -1:
                    q.append(y)
                    bfs_map[y] = bfs_map[x]+1
        if bfs_map[b] == -1:return 0
        d = bfs_map[b]
        path = [b]
        y = b
        while d > 0:
            for x in ent[y]:
                if bfs_map[x] == d-1:
                    path.insert(0,x)
                    y = x
                    d -= 1
                    break
        return path

    def ford_fulkerson(a,b,c):
        ans = 0
        while 1:
            path = bfs(a,b)
            if not path:break
            for i in range(len(path)-1):
                out[path[i]].remove(path[i+1])
                ent[path[i+1]].remove(path[i])
                if not c[path[i+1]][path[i]]:
                    c[path[i+1]][path[i]] = 1
                    out[path[i+1]].append(path[i])
                    ent[path[i]].append(path[i+1])
            ans += 1
        return ans
    n = I()
    r = LIR(n)
    b = LIR(n)
    c = [[0 for i in range(2*n+2)] for i in range(2*n+2)]
    out = [[] for i in range(2*n+2)]
    ent = [[] for i in range(2*n+2)]
    for i in range(n):
        c[0][i+1] = 1
        out[0].append(i+1)
        ent[i+1].append(0)
        for j in range(n):
            if r[i][0] < b[j][0] and r[i][1] < b[j][1]:
                c[i+1][n+j+1] = 1
                out[i+1].append(n+j+1)
                ent[n+j+1].append(i+1)
    for j in range(n):
        c[n+j+1][2*n+1] = 1
        out[n+j+1].append(2*n+1)
        ent[2*n+1].append(n+j+1)
    print(ford_fulkerson(0,2*n+1,c))
#D
def D():
    n = I()
    a = LI()
    b = LI()
    ans = 0
    p = 1
    for k in range(30):
        s = 0
        c = [b[i]%(p*2) for i in range(n)]
        a_ = [a[i]%(p*2) for i in range(n)]
        c.sort()
        a_.sort()
        l1,l2,l3 = 0,0,0
        y = float("inf")
        for x in a_[::-1]:
            if x != y:
                while l1 < n and c[l1] < p-x:l1 += 1
                while l2 < n and c[l2] < 2*p-x:l2 += 1
                while l3 < n and c[l3] < 3*p-x:l3 += 1
            s += n-l2-l1-l3
            y = x
        ans += (s%2)*p
        p *= 2
    print(ans)
#E
def E():
    return

#F
def F():
    return

#G
def G():
    return

#H
def H():
    return

#Solve
if __name__ == "__main__":
    D()

Buggy submission (verdict: Runtime Error):
n = int(input())
a = input()
a = a.split(" ")
b = input()
b = b.split(" ")
s = [0]*n**2
for i in range(n):
    a[i] = int(a[i])
    b[i] = int(b[i])
for i in range(n):
    for j in range(n):
        s[n*i+j] = a[i] + b[j]

bin_xor = [0]*50
for i in range(n**2):
    s[i] = bin(s[i])[2:]
    for j in range(len(s[i])):
        if s[i][-j-1] == "1":
            bin_xor[-j-1] += 1
            bin_xor[-j-1] = bin_xor[-j-1]%2

xor = 0
for i in range(50):
    xor += bin_xor[-i-1]*2**i
print(xor)

Buggy submission (verdict: Runtime Error):
n = int(input())
a = input()
a = a.split(" ")
b = input()
b = b.split(" ")
s = [0]*n**2
for i in range(n):
    a[i] = int(a[i])
    b[i] = int(b[i])
for i in range(n):
    for j in range(n):
        s[n*i+j] = a[i] + b[j]
leng = [0]*n**2
for i in range(n**2):
    s[i] = bin(s[i])[2:]
    leng[i] = len(s[i])
leng = max(leng)

bin_xor = [0]*leng
for i in range(n**2):
    for j in range(len(s[i])):
        if s[i][-j-1] == "1":
            bin_xor[-j-1] += 1
            bin_xor[-j-1] = bin_xor[-j-1]%2

xor = 0
for i in range(leng):
    xor += bin_xor[-i-1]*2**i
print(xor)

Buggy submission (verdict: Runtime Error):
n = int(input())
a = input()
a = a.split(" ")
b = input()
b = b.split(" ")
s = [0]*n**2
for i in range(n):
    a[i] = int(a[i])
    b[i] = int(b[i])
for i in range(n):
    for j in range(n):
        s[n*i+j] = a[i] + b[j]
leng = [0]*n**2
for i in range(n**2):
    s[i] = bin(s[i])[2:]
    leng[i] = len(s[i])
leng = max(leng)

bin_xor = [0]*leng
for i in range(n**2):
    for j in range(len(s[i])):
        if s[i][-j-1] == "1":
            bin_xor[-j-1] += 1
            bin_xor[-j-1] = bin_xor[-j-1]%2

xor = 0
for i in range(leng):
    xor += bin_xor[-i-1]*2**i
print(xor)