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


def main():
    input = sys.stdin.readline
    N = int(input())
    S = input()
    A = S.count('R')*S.count('G')*S.count('B')
    total = 0
    for j in range(1, N-1):
        for i in range(j):
            k = 2*j-i
            order += 1
            if k < len(S):
                if S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
                    total += 1
    print(A - total)


def main2():
    N = int(input())
    S = input()
    A = S.count('R')*S.count('G')*S.count('B')
    order = 0
    for i in range(N-2):
        for j in range(i+1, N-1):
            order += 1
            if 2*j-i < N:
                if S[i] != S[j] and S[i] != S[2*j-i] and S[j] != S[2*j-i]:
                    A -= 1
    print(A)
    print(order)


if __name__ == "__main__":
    main()


Fixed submission:
n = int(input())
s = input()
r,g,b =0,0,0
ls = len(s)
for i in range(ls):
    if s[i]=='R':
        r+=1
    elif s[i]=='G':
        g+=1
    elif s[i]=='B':
        b+=1
cnt =0
for j in range(1,ls-1):
    for i in range(j):
        k = 2*j-i
        if k<ls:
            if s[i]!=s[j] and s[i]!=s[k] and s[j]!=s[k]:
                cnt+=1
print(r*g*b-cnt)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
import collections
input = sys.stdin.readline
N = int(input())
S = input().strip()
assert 1 <= N <= 4000
assert N == len(S)
A = S.count('R')*S.count('G')*S.count('B')
total = 0
for j in range(1, N-1):
    for i in range(j):
        k = 2*j-i
        if k < len(S):
            if S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
                total += 1
# print(c["R"]*c["G"]*c["B"]-total)
print(A - total)


Fixed submission:
n = int(input())
s = input()
r,g,b =0,0,0
ls = len(s)
for i in range(ls):
    if s[i]=='R':
        r+=1
    elif s[i]=='G':
        g+=1
    elif s[i]=='B':
        b+=1
cnt =0
for j in range(1,ls-1):
    for i in range(j):
        k = 2*j-i
        if k<ls:
            if s[i]!=s[j] and s[i]!=s[k] and s[j]!=s[k]:
                cnt+=1
print(r*g*b-cnt)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
import collections
input = sys.stdin.readline
N = int(input())
S = input().strip()
assert 1 <= N <= 4000
assert N == len(S)
r = S.count("R")
g = S.count("G")
b = S.count("B")
total = 0
for j in range(1, N-1):
    for i in range(j):
        k = 2*j-i
        if k < len(S):
            if S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
                total += 1
# print(c["R"]*c["G"]*c["B"]-total)
print(r*g*b - total)


Fixed submission:
n = int(input())
s = input()
r,g,b =0,0,0
ls = len(s)
for i in range(ls):
    if s[i]=='R':
        r+=1
    elif s[i]=='G':
        g+=1
    elif s[i]=='B':
        b+=1
cnt =0
for j in range(1,ls-1):
    for i in range(j):
        k = 2*j-i
        if k<ls:
            if s[i]!=s[j] and s[i]!=s[k] and s[j]!=s[k]:
                cnt+=1
print(r*g*b-cnt)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
import collections
input = sys.stdin.readline
N = int(input())
S = list(input().strip())
assert 1 <= N <= 4000
assert N == len(S)
c = collections.Counter(S)
total = 0
for j in range(1, N-1):
    for i in range(j):
        k = 2*j-i
        if k < len(S):
            if S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
                total += 1
print(c["R"]*c["G"]*c["B"]-total)


Fixed submission:
n = int(input())
s = input()
r,g,b =0,0,0
ls = len(s)
for i in range(ls):
    if s[i]=='R':
        r+=1
    elif s[i]=='G':
        g+=1
    elif s[i]=='B':
        b+=1
cnt =0
for j in range(1,ls-1):
    for i in range(j):
        k = 2*j-i
        if k<ls:
            if s[i]!=s[j] and s[i]!=s[k] and s[j]!=s[k]:
                cnt+=1
print(r*g*b-cnt)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
N = int(input())
S = list(input().strip())
assert 1 <= N <= 4000
assert N == len(S)
r = S.count("R")
g = S.count("G")
b = S.count("B")
total = 0

for j in range(1, N-1):
    for i in range(j):
        k = 2*j-i
        if k < len(S):
            if S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
                total += 1
print(r*g*b-total)


Fixed submission:
n = int(input())
s = input()
r,g,b =0,0,0
ls = len(s)
for i in range(ls):
    if s[i]=='R':
        r+=1
    elif s[i]=='G':
        g+=1
    elif s[i]=='B':
        b+=1
cnt =0
for j in range(1,ls-1):
    for i in range(j):
        k = 2*j-i
        if k<ls:
            if s[i]!=s[j] and s[i]!=s[k] and s[j]!=s[k]:
                cnt+=1
print(r*g*b-cnt)