|a|right| |a
 |1|right|0|a
 |2|left|<|2
0|1|right|0|1
0|b|right|0|b
0|2|right|1|b
1|2|right|1|2
1|3|right|1|3
1| |left|a|3
a|3|left|a|3
a|2|left|a|2
a|b|right|c|b
a|1|left|a|1
a|a|right| |a
a|1|right|b|1
a|a|right|b|a
b|b|right|b|2
b|3|left|c|3
b|2|left|c|2
b|1|left|c|1
b|a|right| |a
c|2|right|1|b
c|3|left|c|3
c|b|left|c|2
c|1|left|c|1
c| |right|>| 
c|a|right|d|a
d|1|right|0|a
d|2|left|<|2
<|1|left|<|1
<|a|left|<|a
<| |right|>| 
>|1|right|>| 
>|a|right|>| 
>|2|right|>| 
>|3|stop|>|3