Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in R:
	for j in G:
		d=abs(i-j)
		min_n=min(i,j)
		max_n=max(i,j)
		if max_n+d in B:
			c+=1
		if (i+j)%2==0 and (i+j)//2 in B:
			c+=1
		if min_n-d in B:
			c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i+1)
	elif S[i]=='G':
		G.append(i+1)
	else:
		B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in R:
	for j in B:
		d=abs(i-j)
		min_n=min(i,j)
		max_n=max(i,j)
		if max_n+d in G:
			c+=1
		if (i+j)%2==0 and (i+j)//2 in G:
			c+=1
		if min_n-d in G:
			c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i+1)
	elif S[i]=='G':
		G.append(i+1)
	else:
		B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in R:
	for j in G:
		d=abs(i-j)
		min_n=min(i,j)
		max_n=max(i,j)
		if max_n+d in B:
			c+=1
		if (i+j)%2==0 and (i+j)//2 in B:
			c+=1
		if min_n-d in B:
			c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i+1)
	elif S[i]=='G':
		G.append(i+1)
	else:
		B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in R:
	for j in G:
		d=abs(i-j)
		min_n=min(i,j)
		max_n=max(i,j)
		if max_n+d in B:
			c+=1
		if (i+j)/2 in B:
			c+=1
		if min_n-d in B:
			c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i+1)
	elif S[i]=='G':
		G.append(i+1)
	else:
		B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in R:
	for j in G:
		d=abs(i-j)
		min_n=min(i,j)-d
		max_n=max(i,j)+d
		if max_n in B:
			c+=1
		if (i+j)/2 in B:
			c+=1
		if min_n in B:
			c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
    if S[i]=='R':
        R.append(i+1)
    elif S[i]=='G':
        G.append(i+1)
    else:
        B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in R:
    for j in B:
        min_n=min(i,j)
        max_n=max(i,j)
        d=abs(i-j)
        if max_n+d in G:
            c+=1
        if (i+j)%2==0 and (i+j)//2 in G:
            c+=1
        if min_n-d in G:
            c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
    if S[i]=='R':
        R.append(i+1)
    elif S[i]=='G':
        G.append(i+1)
    else:
        B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in R:
    for j in B:
        min_n=min(i,j)
        max_n=max(i,j)
        d=abs(i-j)
        if max_n+d in G:
            c+=1
        if (i+j)%2==0 and (i+j)//2 in G:
            c+=1
        if min_n-d in G:
            c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
    if S[i]=='R':
        R.append(i+1)
    elif S[i]=='G':
        G.append(i+1)
    else:
        B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in G:
    for j in B:
        min_n=min(i,j)
        max_n=max(i,j)
        d=abs(i-j)
        if max_n+d in R:
            c+=1
        if (i+j)%2==0 and (i+j)//2 in R:
            c+=1
        if min_n-d in R:
            c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
    if S[i]=='R':
        R.append(i+1)
    elif S[i]=='G':
        G.append(i+1)
    else:
        B.append(i+1)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in G:
    for j in B:
        min_n=min(i,j)
        max_n=max(i,j)
        d=abs(i-j)
        if max_n+d in R:
            c+=1
        if (i+j)%2==0 and (i+j)//2 in R:
            c+=1
        if min_n-d in R:
            c+=1

print(r*g*b-c)

Fixed submission:
n=int(input())
S=input()
R=[]
G=[]
B=[]
for i in range(n):
	if S[i]=='R':
		R.append(i)
	elif S[i]=='G':
		G.append(i)
	else:
		B.append(i)
r=len(R)
g=len(G)
b=len(B)

c=0
for i in range(n):
	for j in range(i+1,n):
		k=2*j-i
		if k<n:
			if len(set([S[i],S[j],S[k]]))==3:
				c+=1

print(r*g*b-c)