Buggy python submission (verdict: Time Limit Exceeded):
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n-1):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if sum([a[i],a[j],a[c]])==6:
                ans -= 1
print(ans)

Fixed submission:
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i]+a[j]+a[c]==6:
                ans -= 1
        else:
            break
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import collections
n = int(input())
a = list(input())
b = collections.Counter(a)
ans =b['R']*b['G']*b['B']
for i in range(n-2):
    for j in range(i+1,n-1):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i] != a[j] and a[i] != a[c] and a[j] != a[c]:
                ans -= 1
print(ans)

Fixed submission:
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i]+a[j]+a[c]==6:
                ans -= 1
        else:
            break
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
n = int(input())
s = input()
s = s.replace('R','0')
s = s.replace('G','1')
s = s.replace('B','2')
s = s.replace('\n','')
s = tuple(map(int,s))
rgb = [[0 for _ in range(3)] for _ in range(n+1)]
for i in range(n):
    for j in range(3):
        rgb[i+1][j] = rgb[i][j]
    rgb[i+1][s[i]] = rgb[i][s[i]] +1
rgb = tuple(rgb)
ans = 0
for i in range(n):
    a = s[i]
    for j in range(i+1,n):
        b = s[j]
        if a != b:
            c = 3 -a- b
            ans += rgb[n][c] - rgb[j+1][c]
            if 2*j-i < n and s[2*j-i] == c:
                ans -= 1

print(ans)


Fixed submission:
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i]+a[j]+a[c]==6:
                ans -= 1
        else:
            break
print(ans)

Buggy python submission (verdict: Runtime Error):
import sys
input = sys.stdin.readline
n = int(input())
s = input()
s = s.replace('R','0')
s = s.replace('G','1')
s = s.replace('B','2')
s = tuple(map(int,s))
rgb = [[0 for _ in range(3)] for _ in range(n+1)]
for i in range(n):
    for j in range(3):
        rgb[i+1][j] = rgb[i][j]
    rgb[i+1][s[i]] = rgb[i][s[i]] +1
rgb = tuple(rgb)
ans = 0
for i in range(n):
    a = s[i]
    for j in range(i+1,n):
        b = s[j]
        if a != b:
            c = 3 -a- b
            ans += rgb[n][c] - rgb[j+1][c]
            if 2*j-i < n and s[2*j-i] == c:
                ans -= 1

print(ans)


Fixed submission:
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i]+a[j]+a[c]==6:
                ans -= 1
        else:
            break
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
s = s.replace('R','0')
s = s.replace('G','1')
s = s.replace('B','2')
s = tuple(map(int,s))
rgb = [[0 for _ in range(3)] for _ in range(n+1)]
for i in range(n):
    for j in range(3):
        rgb[i+1][j] = rgb[i][j]
    rgb[i+1][s[i]] = rgb[i][s[i]] +1
rgb = tuple(rgb)
ans = 0
for i in range(n):
    a = s[i]
    for j in range(i+1,n):
        b = s[j]
        if a != b:
            c = 3 -a- b
            ans += rgb[n][c] - rgb[j+1][c]
            if 2*j-i < n and s[2*j-i] == c:
                ans -= 1

print(ans)


Fixed submission:
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i]+a[j]+a[c]==6:
                ans -= 1
        else:
            break
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
s = s.replace('R','0')
s = s.replace('G','1')
s = s.replace('B','2')
s = tuple(map(int,s))
rgb = [[0 for _ in range(3)] for _ in range(n+1)]
for i in range(n):
    for j in range(3):
        rgb[i+1][j] = rgb[i][j]
    rgb[i+1][s[i]] = rgb[i][s[i]] +1

ans = 0
for i in range(n):
    a = s[i]
    for j in range(i+1,n):
        b = s[j]
        if a != b:
            c = 3 -a- b
            ans += rgb[n][c] - rgb[j+1][c]
            if 2*j-i < n and s[2*j-i] == c:
                ans -= 1

print(ans)


Fixed submission:
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i]+a[j]+a[c]==6:
                ans -= 1
        else:
            break
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
s = input()
s = s.replace('R','0')
s = s.replace('G','1')
s = s.replace('B','2')
s = list(map(int,s))
rgb = [[0 for _ in range(3)] for _ in range(n+1)]
for i in range(n):
    for j in range(3):
        rgb[i+1][j] = rgb[i][j]
    rgb[i+1][s[i]] = rgb[i][s[i]] +1

ans = 0
for i in range(n):
    a = s[i]
    for j in range(i+1,n):
        b = s[j]
        if a != b:
            c = 3 -a- b
            ans += rgb[n][c] - rgb[j+1][c]
            if 2*j-i < n and s[2*j-i] == c:
                ans -= 1

print(ans)


Fixed submission:
import collections
n = int(input())
a = input()
a = a.replace('R','1')
a = a.replace('G','2')
a = a.replace('B','3')
a = tuple(map(int,list(a)))
b = collections.Counter(a)
ans =b[3]*b[1]*b[2]
for i in range(n-2):
    for j in range(i+1,n):
        if a[i] == a[j]:
            continue
        c = j*2 -i
        if c < n:
            if a[i]+a[j]+a[c]==6:
                ans -= 1
        else:
            break
print(ans)