a
b
b
a
x1
a
c
a
b
x1
a
c
x1
c
c
a
x1
c
c
c
x1
b
c
b
x1
2.2
a
c
x1
c
a
x1
a
b
b
a
x1
c
a
b
x1
a
b
b
a
x1
a
b
x1
a
b
b
a
x1
a
c
a
b
x1
a
c
x1
a
x1
a
c
x1
c
c
a
x1
c
c
c
x1
c
b
x1
true
a
c
x1
a
x1
a
b
b
a
x1
a
c
a
b
x1
a
b
b
a
x1
a
b
x1
true
a
1
1
41063
b
1
1
0
c
1
1
0
c
1
0
a
1
1
0
a
b
b
a
x1
a
c
a
b
x1
a
c
x1
a
x1
a
b
b
a
x1
a
c
a
b
x1
c
c
c
x1
b
c
b
x1
a
c
x1
c
c
a
x1
a
b
b
a
x1
a
c
a
b
x1
a
c
x1
a
x1
true
2
1
a
1
3751
1
b
1
1
1
0
0
1
0
0
c
1
0
0
0
1
1
0
0
c
1
0
0
a
1
0
0
1
0
1
0
0
a
c
x1
a
x1
a
b
b
a
x1
a
c
a
b
x1
c
c
c
x1
b
c
b
x1
a
c
x1
c
c
a
x1
a
c
x1
a
x1
true
Failed!
NaTT
certifiable-1.6