pythondef solve(N, XS):
if N == 1:
return 0
a = abs(XS[1] - XS[0])
if N == 2:
return a
b = abs(XS[2] - XS[0])
if N == 3:
return b
for i in range(3, N):
v = min(
a + abs(XS[i - 2] - XS[i]),
b + abs(XS[i - 1] - XS[i]),
)
a = b
b = v
return v