calls = 0
def f ( length, last ):
    global calls
    calls += 1
    
    if length <= 1: return 1;
    if last == 1: return f( length-1, 0) + f(length-1, 1)
    if last == 0: return f( length-1, 1) + f(length-2, 1)


for length in range(2, 40):
    calls = 0;
    print( length, f(length,0)+f(length,1), " calls: ", str(calls) )