Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
r = []
g = []
b = []
for i in range(len(s)):
    t = s[i]
    if t == 'R':
        r.append(i+1)
    elif t == 'G':
        g.append(i+1)
    else:
        b.append(i+1)

ans = 0
for i in r:
    for j in g:
        for k in b:
            if i < j < k:
                if j-i != k-j:
                    ans += 1
for i in g:
    for j in b:
        for k in r:
            if i < j < k:
                if j-i != k-j:
                    ans += 1
for i in b:
    for j in r:
        for k in g:
            if i < j < k:
                if j-i != k-j:
                    ans += 1
for i in r:
    for j in b:
        for k in g:
            if i < j < k:
                if j-i != k-j:
                    ans += 1
for i in g:
    for j in r:
        for k in b:
            if i < j < k:
                if j-i != k-j:
                    ans += 1
for i in b:
    for j in g:
        for k in r:
            if i < j < k:
                if j-i != k-j:
                    ans += 1

"""
ans = 0
for i in range(1, n+1):
    for j in range(i, n+1):
        for k in range(j, n+1):
            if sl[i-1] != sl[j-1] and sl[j-1] != sl[k-1] and sl[k-1] != sl[i-1]:
                if j-i != k-j:
                    ans += 1
"""

print(ans)

Fixed submission:
n = int(input())
s = input()

r = []
g = []
b = []
for i in range(len(s)):
    t = s[i]
    if t == 'R':
        r.append(i+1)
    elif t == 'G':
        g.append(i+1)
    else:
        b.append(i+1)

ans = len(r) * len(g) * len(b)

for i in range(1, int((n-1)/2)+1):
    for j in range(n-i-i, 0, -1):
        if s[j-1] != s[j+i-1] and s[j+i-1] != s[j+i+i-1] and s[j+i+i-1] != s[j-1]:
            ans -= 1

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
sl = input()
# sl = [s[i] for i in range(len(s))]

ans = 0
for i in range(1, n+1):
    for j in range(i, n+1):
        for k in range(j, n+1):
            if sl[i-1] != sl[j-1] and sl[j-1] != sl[k-1] and sl[k-1] != sl[i-1]:
                if j-i != k-j:
                    ans += 1

print(ans)

Fixed submission:
n = int(input())
s = input()

r = []
g = []
b = []
for i in range(len(s)):
    t = s[i]
    if t == 'R':
        r.append(i+1)
    elif t == 'G':
        g.append(i+1)
    else:
        b.append(i+1)

ans = len(r) * len(g) * len(b)

for i in range(1, int((n-1)/2)+1):
    for j in range(n-i-i, 0, -1):
        if s[j-1] != s[j+i-1] and s[j+i-1] != s[j+i+i-1] and s[j+i+i-1] != s[j-1]:
            ans -= 1

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
sl = [s[i] for i in range(len(s))]

ans = 0
for i in range(1, n+1):
    for j in range(i, n+1):
        for k in range(j, n+1):
            if sl[i-1] != sl[j-1] and sl[j-1] != sl[k-1] and sl[k-1] != sl[i-1]:
                if j-i != k-j:
                    ans += 1

print(ans)

Fixed submission:
n = int(input())
s = input()

r = []
g = []
b = []
for i in range(len(s)):
    t = s[i]
    if t == 'R':
        r.append(i+1)
    elif t == 'G':
        g.append(i+1)
    else:
        b.append(i+1)

ans = len(r) * len(g) * len(b)

for i in range(1, int((n-1)/2)+1):
    for j in range(n-i-i, 0, -1):
        if s[j-1] != s[j+i-1] and s[j+i-1] != s[j+i+i-1] and s[j+i+i-1] != s[j-1]:
            ans -= 1

print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
sl = [s[i] for i in range(len(s))]

ans = 0
for i in range(1, n+1):
    for j in range(i, n+1):
        for k in range(j, n+1):
            if sl[i-1] != sl[j-1] and sl[j-1] != sl[k-1] and sl[k-1] != sl[i-1]:
                if j-i != k-j:
                    ans += 1

print(ans)

Fixed submission:
n = int(input())
s = input()

r = []
g = []
b = []
for i in range(len(s)):
    t = s[i]
    if t == 'R':
        r.append(i+1)
    elif t == 'G':
        g.append(i+1)
    else:
        b.append(i+1)

ans = len(r) * len(g) * len(b)

for i in range(1, int((n-1)/2)+1):
    for j in range(n-i-i, 0, -1):
        if s[j-1] != s[j+i-1] and s[j+i-1] != s[j+i+i-1] and s[j+i+i-1] != s[j-1]:
            ans -= 1

print(ans)