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

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

#すべての値が同じときは半分を置換する
if odd == even:
    print(len(odd))
    input()
    exit(0)

#奇数列，偶数列それぞれの最頻の文字が同じ場合は，いずれかを2番目に多い文字に置換しなければならない
if o.most_common()[0][0] == e.most_common()[0][0]:
    if len(o.most_common()) > 1 and len(e.most_common()) <= 1:
        maxoddcnt = o.most_common()[1][1]
    if len(o.most_common()) <= 1 and len(e.most_common()) > 1:
        maxevencnt = e.most_common()[1][1]
    if o.most_common()[1][1] + e.most_common()[0][1] >= o.most_common()[0][1] + e.most_common()[1][1]:
        maxoddcnt = o.most_common()[1][1]
    else: #if o.most_common()[1][1] + e.most_common()[0][1] <= o.most_common()[0][1] + e.most_common()[1][1] :
        maxevencnt = e.most_common()[1][1]

print(len(odd)-maxoddcnt+len(even)-maxevencnt)


Fixed submission:
import collections

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

#すべての値が同じときは半分を置換する
if odd == even and len(o.most_common()) == 1:
    print(len(odd))
    exit(0)

#奇数列，偶数列それぞれの最頻の文字が同じ場合は，いずれかを2番目に多い文字に置換しなければならない
if o.most_common()[0][0] == e.most_common()[0][0]:
    if len(o.most_common()) > 1 and len(e.most_common()) <= 1:
        maxoddcnt = o.most_common()[1][1]
    if len(o.most_common()) <= 1 and len(e.most_common()) > 1:
        maxevencnt = e.most_common()[1][1]
    if o.most_common()[1][1] + e.most_common()[0][1] >= o.most_common()[0][1] + e.most_common()[1][1]:
        maxoddcnt = o.most_common()[1][1]
    else: #if o.most_common()[1][1] + e.most_common()[0][1] <= o.most_common()[0][1] + e.most_common()[1][1] :
        maxevencnt = e.most_common()[1][1]

print(len(odd)-maxoddcnt+len(even)-maxevencnt)

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

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

#すべての値が同じときは半分を置換する
if odd == even:
    print(len(odd))
    exit(0)

#奇数列，偶数列それぞれの最頻の文字が同じ場合は，いずれかを2番目に多い文字に置換しなければならない
if o.most_common()[0][0] == e.most_common()[0][0]:
    if len(o.most_common()) > 1 and len(e.most_common()) <= 1:
        maxoddcnt = o.most_common()[1][1]
    if len(o.most_common()) <= 1 and len(e.most_common()) > 1:
        maxevencnt = e.most_common()[1][1]
    if o.most_common()[1][1] + e.most_common()[0][1] >= o.most_common()[0][1] + e.most_common()[1][1]:
        maxoddcnt = o.most_common()[1][1]
    else: #if o.most_common()[1][1] + e.most_common()[0][1] <= o.most_common()[0][1] + e.most_common()[1][1] :
        maxevencnt = e.most_common()[1][1]
        input()

print(len(odd)-maxoddcnt+len(even)-maxevencnt)


Fixed submission:
import collections

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

#すべての値が同じときは半分を置換する
if odd == even and len(o.most_common()) == 1:
    print(len(odd))
    exit(0)

#奇数列，偶数列それぞれの最頻の文字が同じ場合は，いずれかを2番目に多い文字に置換しなければならない
if o.most_common()[0][0] == e.most_common()[0][0]:
    if len(o.most_common()) > 1 and len(e.most_common()) <= 1:
        maxoddcnt = o.most_common()[1][1]
    if len(o.most_common()) <= 1 and len(e.most_common()) > 1:
        maxevencnt = e.most_common()[1][1]
    if o.most_common()[1][1] + e.most_common()[0][1] >= o.most_common()[0][1] + e.most_common()[1][1]:
        maxoddcnt = o.most_common()[1][1]
    else: #if o.most_common()[1][1] + e.most_common()[0][1] <= o.most_common()[0][1] + e.most_common()[1][1] :
        maxevencnt = e.most_common()[1][1]

print(len(odd)-maxoddcnt+len(even)-maxevencnt)

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

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

#すべての値が同じときは半分を置換する
if odd == even:
    print(len(odd))
    exit(0)

#奇数列，偶数列それぞれの最頻の文字が同じ場合は，いずれかを2番目に多い文字に置換しなければならない
if o.most_common()[0][0] == e.most_common()[0][0]:
    if len(o.most_common()) > 1 and len(e.most_common()) <= 1:
        maxoddcnt = o.most_common()[1][1]
    if len(o.most_common()) <= 1 and len(e.most_common()) > 1:
        maxevencnt = e.most_common()[1][1]
    if o.most_common()[1][1] + e.most_common()[0][1] >= o.most_common()[0][1] + e.most_common()[1][1]:
        maxoddcnt = o.most_common()[1][1]
        input()
    else: #if o.most_common()[1][1] + e.most_common()[0][1] <= o.most_common()[0][1] + e.most_common()[1][1] :
        maxevencnt = e.most_common()[1][1]

print(len(odd)-maxoddcnt+len(even)-maxevencnt)


Fixed submission:
import collections

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

#すべての値が同じときは半分を置換する
if odd == even and len(o.most_common()) == 1:
    print(len(odd))
    exit(0)

#奇数列，偶数列それぞれの最頻の文字が同じ場合は，いずれかを2番目に多い文字に置換しなければならない
if o.most_common()[0][0] == e.most_common()[0][0]:
    if len(o.most_common()) > 1 and len(e.most_common()) <= 1:
        maxoddcnt = o.most_common()[1][1]
    if len(o.most_common()) <= 1 and len(e.most_common()) > 1:
        maxevencnt = e.most_common()[1][1]
    if o.most_common()[1][1] + e.most_common()[0][1] >= o.most_common()[0][1] + e.most_common()[1][1]:
        maxoddcnt = o.most_common()[1][1]
    else: #if o.most_common()[1][1] + e.most_common()[0][1] <= o.most_common()[0][1] + e.most_common()[1][1] :
        maxevencnt = e.most_common()[1][1]

print(len(odd)-maxoddcnt+len(even)-maxevencnt)

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

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

if o.most_common()[0][0] == e.most_common()[0][0]:
    if o.most_common()[0][1] > e.most_common()[0][1]:
        maxevencnt = e.most_common()[1][1]
    else:
        maxoddcnt = o.most_common()[1][1]

print(len(odd)-maxoddcnt+len(even)-maxevencnt)


Fixed submission:
import collections

n = input()
line = input().split()
odd = line[::2]
even = line[1::2]
o = collections.Counter(odd)
e = collections.Counter(even)
maxoddcnt = o.most_common()[0][1]
maxevencnt = e.most_common()[0][1]

#すべての値が同じときは半分を置換する
if odd == even and len(o.most_common()) == 1:
    print(len(odd))
    exit(0)

#奇数列，偶数列それぞれの最頻の文字が同じ場合は，いずれかを2番目に多い文字に置換しなければならない
if o.most_common()[0][0] == e.most_common()[0][0]:
    if len(o.most_common()) > 1 and len(e.most_common()) <= 1:
        maxoddcnt = o.most_common()[1][1]
    if len(o.most_common()) <= 1 and len(e.most_common()) > 1:
        maxevencnt = e.most_common()[1][1]
    if o.most_common()[1][1] + e.most_common()[0][1] >= o.most_common()[0][1] + e.most_common()[1][1]:
        maxoddcnt = o.most_common()[1][1]
    else: #if o.most_common()[1][1] + e.most_common()[0][1] <= o.most_common()[0][1] + e.most_common()[1][1] :
        maxevencnt = e.most_common()[1][1]

print(len(odd)-maxoddcnt+len(even)-maxevencnt)