i
t
e
r
a
t
i
o
n
s
t
e
p
0
1
2
3
4
5
6
0
.
2
0
.
4
0
.
6
0
.
8
1
.
0
-
1
.
5
-
1
.
0
-
0
.
5
0
.
5
1
.
0
1
.
5
2
.
0
f
(
x
)
I
t
e
r
a
t
i
o
n
=
0
x
_
n
=
0
.
3
5
f
(
x
_
n
)
=
1
.
7
4
8
8
3
