alp = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
def f(x, y, c):
    if x[-1] == y:return c == 5
    elif 'M' in x or c > 5:return 0
    else:return f(x + alp[alp.index(x[-1]) + 1], y, c + 1) + f(x + alp[alp.index(x[-1]) + 4], y, c + 1)

print(f('A', 'O', 0))