Buggy python submission (verdict: Runtime Error):
from copy import deepcopy
n = int(input())
v = list(map(int,input().split()))

odd = []
even = []

if len(set(v)) == 1:
    print(n//2)
    exit()

for i in range(n):
    if i%2 == 0:
        even.append(v[i])
    else:
        odd.append(v[i])

box_e = [0]*int(1e5+1)
box_o = [0]*int(1e5+1)
e = {}
o = {}
for i in range(n//2):
    if even[i] in e:
        e[even[i]] += 1
    else:
        e[even[i]] = 1
    if odd[i] in o:
        o[odd[i]] += 1
    else:
        o[odd[i]] = 1
values_e = list(e.values())
keys_e = list(e.keys())
values_o = list(o.values())
keys_o = list(o.keys())
Oddlist = []
Evenlist = []
for i in range(len(keys_e)):
    Evenlist.append([values_e[i],keys_e[i]])
for j in range(len(keys_o)):
    Oddlist.append([values_o[i],keys_o[i]])
Evenlist.sort()
Oddlist.sort()
mode_even = Evenlist[-1]
mode_even_2 = 0
if len(keys_e) >= 2:
    mode_even_2 = Evenlist[-2]
mode_odd = Oddlist[-1]
mode_odd_2 = 0
if len(keys_o) >= 2:
    mode_even_2 = Oddlist[-2]

ans = 0

if mode_even[1] != mode_odd[1]:
    ##print("hoge")
    for i in range(n//2):
        if odd[i] != mode_odd[1]:
            ans += 1
        if even[i] != mode_even[1]:
            ans += 1
else:
    if mode_even[0] > mode_odd[0]:
        for i in range(n//2):
            if odd[i] != mode_odd[1]:
                ans += 1
            if even[i] != mode_even_2[1]:
                ans += 1
    else:
        for i in range(n//2):
            if odd[i] != mode_odd_2[1]:
                ans += 1
            if even[i] != mode_even[1]:
                ans += 1
print(ans)

Fixed submission:
from collections import Counter

def main():
    
    N = int(input())
    V = list(map(int,input().split()))
    odd = V[1::2]
    even = V[0::2]
    mode_o = Counter(odd).most_common()
    mode_o.append([0,0])
    mode_e = Counter(even).most_common()
    mode_e.append([0,0])
    ans = 0
    if mode_o[0][0] != mode_e[0][0]:
        ans = N-mode_o[0][1]-mode_e[0][1]
    else:
        ans = N - max(mode_e[0][1]+mode_o[1][1],mode_e[1][1]+mode_o[0][1])
    print(ans)

if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
n = int(input())
v = list(map(int,input().split()))

odd = []
even = []

if len(set(v)) == 1:
    print(n//2)
    exit()

for i in range(n):
    if i%2 == 0:
        even.append(v[i])
    else:
        odd.append(v[i])

box_e = [0]*int(1e5)
box_o = [0]*int(1e5)

for i in range(n//2):
    box_e[even[i]] += 1
    box_o[odd[i]] += 1

mode_e = box_e.index(max(box_e))
mode_o = box_o.index(max(box_o))

ans = 0

for i in range(n//2):
    if odd[i] != mode_o:
        ans += 1
    if even[i] != mode_e:
        ans += 1

print(ans)

Fixed submission:
from collections import Counter

def main():
    
    N = int(input())
    V = list(map(int,input().split()))
    odd = V[1::2]
    even = V[0::2]
    mode_o = Counter(odd).most_common()
    mode_o.append([0,0])
    mode_e = Counter(even).most_common()
    mode_e.append([0,0])
    ans = 0
    if mode_o[0][0] != mode_e[0][0]:
        ans = N-mode_o[0][1]-mode_e[0][1]
    else:
        ans = N - max(mode_e[0][1]+mode_o[1][1],mode_e[1][1]+mode_o[0][1])
    print(ans)

if __name__ == "__main__":
    main()