v0 = 1
v1 = 0
v2 = 0
for i in range(10):
v0, v1, v2 = v0 + v1 + v2, v0, v1
print(i, v0)
djAgPSAxCnYxID0gMAp2MiA9IDAKZm9yIGkgaW4gcmFuZ2UoMTApOgogICAgdjAsIHYxLCB2MiA9IHYwICsgdjEgKyB2MiwgdjAsIHYxCiAgICBwcmludChpLCB2MCk=
(0, 1)
(1, 2)
(2, 4)
(3, 7)
(4, 13)
(5, 24)
(6, 44)
(7, 81)
(8, 149)
(9, 274)