Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

dic = {}
Ans = 0

for i in range(2**N):
    red,blue = "",""
    bits = bin(2**N+i)[3:]
    for j in range(N):
        if bits[j]=="0":
            red += S1[j]
        else:
            blue += S1[j]
    key = red+"-"+blue[::-1]
    if key not in dic.keys():
        dic[key] = 1
    else:
        dic[key] += 1

for i in range(2**N):
    red,blue = "",""
    bits = bin(2**N+i)[3:]
    for j in range(N):
        if bits[j]=="1":
            red += S2[j]
        else:
            blue += S2[j]
    key = red+"-"+blue[::-1]
    if key in dic.keys():
        Ans += dic[key]
        
print(Ans)

Fixed submission:
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

dic = {}
Ans = 0
keys = []

for i in range(2**N):
    red,blue = "",""
    red2,blue2 = "",""
    bits = bin(2**N+i)[3:]
    for j in range(N):
        if bits[j]=="0":
            red   += S1[j]
            red2 += S2[j]
        else:
            blue += S1[j]
            blue2 += S2[j]
    keys.append(red2+"-"+blue2)
    key = red+"-"+blue
    if key not in dic.keys():
        dic[key] = 1
    else:
        dic[key] += 1

for k in keys:
    Ans += dic.get(k,0)

print(Ans)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

from itertools import product
B = list(product([0,1], repeat=N))

D1 = {}
Ans = 0

for bb in B:
    red,blue = "",""
    cnt = 0
    for i,b in enumerate(bb):
        if b == 0:
            red += S1[i]
            cnt += 1
        else:
            blue += S1[i]
    key = (cnt,red+blue[::-1])
    if key not in D1.keys():
        D1[key] = 1
    else:
        D1[key] += 1

for bb in B:
    red,blue = "",""
    cnt = 0
    for i,b in enumerate(bb):
        if b == 1:
            red += S2[i]
            cnt += 1
        else:
            blue += S2[i]
    key = (cnt,red+blue[::-1])
    if key in D1.keys():
        Ans += D1[key]

print(Ans)

Fixed submission:
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

dic = {}
Ans = 0
keys = []

for i in range(2**N):
    red,blue = "",""
    red2,blue2 = "",""
    bits = bin(2**N+i)[3:]
    for j in range(N):
        if bits[j]=="0":
            red   += S1[j]
            red2 += S2[j]
        else:
            blue += S1[j]
            blue2 += S2[j]
    keys.append(red2+"-"+blue2)
    key = red+"-"+blue
    if key not in dic.keys():
        dic[key] = 1
    else:
        dic[key] += 1

for k in keys:
    Ans += dic.get(k,0)

print(Ans)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

from itertools import product
B = list(product([0,1], repeat=N))

D1 = {}
Ans = 0

for bb in B:
    red,blue = "",""
    cnt = 0
    for i,b in enumerate(bb):
        if b == 0:
            red += S1[i]
            cnt += 1
        else:
            blue += S1[i]
    key = (cnt,red+blue[::-1])
    if key not in D1.keys():
        D1[key] = 1
    else:
        D1[key] += 1

for bb in B:
    red,blue = "",""
    cnt = 0
    for i,b in enumerate(bb):
        if b == 1:
            red += S2[i]
            cnt += 1
        else:
            blue += S2[i]
    key = (cnt,red+blue[::-1])
    if key in D1.keys():
        Ans += D1[key]

print(Ans)

Fixed submission:
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

dic = {}
Ans = 0
keys = []

for i in range(2**N):
    red,blue = "",""
    red2,blue2 = "",""
    bits = bin(2**N+i)[3:]
    for j in range(N):
        if bits[j]=="0":
            red   += S1[j]
            red2 += S2[j]
        else:
            blue += S1[j]
            blue2 += S2[j]
    keys.append(red2+"-"+blue2)
    key = red+"-"+blue
    if key not in dic.keys():
        dic[key] = 1
    else:
        dic[key] += 1

for k in keys:
    Ans += dic.get(k,0)

print(Ans)

Buggy python submission (verdict: Time Limit Exceeded):
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

from itertools import product
B = list(product([0,1], repeat=N))

D1 = {}
Ans = 0

for bb in B:
    red,blue = "",""
    cnt = 0
    for i,b in enumerate(bb):
        if b == 0:
            red += S1[i]
            cnt += 1
        else:
            blue += S1[i]
    key = (cnt,red+blue[::-1])
    if key not in D1.keys():
        D1[key] = 1
    else:
        D1[key] += 1

for bb in B:
    red,blue = "",""
    cnt = 0
    for i,b in enumerate(bb):
        if b == 1:
            red += S2[i]
            cnt += 1
        else:
            blue += S2[i]
    key = (cnt,red+blue[::-1])
    if key in D1.keys():
        Ans += D1[key]

print(Ans)

Fixed submission:
N = int(input())
S = input()

S1,S2 = S[:N],S[N:][::-1]

dic = {}
Ans = 0
keys = []

for i in range(2**N):
    red,blue = "",""
    red2,blue2 = "",""
    bits = bin(2**N+i)[3:]
    for j in range(N):
        if bits[j]=="0":
            red   += S1[j]
            red2 += S2[j]
        else:
            blue += S1[j]
            blue2 += S2[j]
    keys.append(red2+"-"+blue2)
    key = red+"-"+blue
    if key not in dic.keys():
        dic[key] = 1
    else:
        dic[key] += 1

for k in keys:
    Ans += dic.get(k,0)

print(Ans)