s = input() n = len(s) D = [True for i in range(n+1)] for i in range(n): if s[i] == 'N': D[i+1] = False ans = 0 for i in range(1,n+1): if D[i]: ans += 1 for j in range(i,n+1,i): D[j] = not D[j] print(ans)