c
a
b
a
x1
a
b
a
a
c
a
b
c
a
b
x1
2.2
c
a
b
a
x1
c
a
b
x1
c
a
b
a
x1
c
a
b
c
a
b
x1
true
c
a
b
a
x1
c
a
b
c
a
b
x1
c
a
b
a
x1
c
a
b
x1
true
2
1
a
1
1
51668
1
b
1
0
1
0
0
1
28579
51666
c
1
0
1
1
1
1
0
74755
c
1
0
1
1
1
1
0
0
c
a
b
a
x1
a
b
a
a
c
a
b
c
a
b
x1
NaTT
certifiable-1.6