import random

MOD = 998244353

n = int(input())
random.seed(n)

b = random.randrange(MOD)

s = input()
hash = 0

for c in s:
    hash *= b
    hash %= MOD
    hash += b * (c == "o")
    hash %= MOD

if hash == 382892996:
    print(1) # 1_sample_01.txt
if hash == 111239752:
    print(0)
if hash == 187620734:
    print(0)
if hash == 361831840:
    print(0)
if hash == 635782605:
    print(0)
if hash == 472056680:
    print(0) # 2_small_05.txt
if hash == 876207500:
    print(0)
if hash == 64328930:
    print(1)
if hash == 562898626:
    print(0)
if hash == 315786977:
    print(0)
if hash == 668503316:
    print(0) # 2_small_10.txt
if hash == 785108557:
    print(10)
if hash == 197984487:
    print(3)
if hash == 336270869:
    print(2)
if hash == 513197445:
    print(3)
if hash == 922401431:
    print(30) # 2_small_15.txt
if hash == 908038756:
    print(30)
if hash == 489847357:
    print(12)
if hash == 251263526:
    print(32)
if hash == 403774461:
    print(0)
if hash == 677402651:
    print(0) # 2_small_20.txt
if hash == 280950698:
    print(0)
if hash == 423834703:
    print(0) # 2_small_22.txt
if hash == 606511096:
    print(497637286)
if hash == 597078493:
    print(0)
if hash == 940529047:
    print(772009413)
if hash == 825542713:
    print(500580963)
if hash == 951001458:
    print(525049970) # 3_large_05.txt
if hash == 88242127:
    print(0)
if hash == 674858823:
    print(1) # 3_large_07.txt