N = int(input().strip())
S = input().strip()

cnt = 0

for i in range(N-2):
  n = 1
  while True:
    if n*2+i >= N:
      break
    
    #print('0:{} 1:{} 2:{}'.format(i, i+n, i+n*2))
    if S[i] + S[i+n] + S[i+n*2] == 'UMG':
      cnt += 1
    
    n+= 1

print(cnt)