a
a
a
x1
b
b
x1
b
b
b
x1
c
d
x1
c
x1
a
a
x1
d
x1
c
x1
2.2
b
b
b
x1
d
x1
a
a
a
x1
b
x1
d
x1
c
x1
a
a
a
x1
b
b
x1
c
x1
a
a
x1
b
b
b
x1
c
d
x1
c
x1
a
x1
true
c
x1
a
x1
b
b
b
x1
c
d
x1
c
x1
a
a
x1
a
a
a
x1
b
x1
a
a
a
x1
b
b
x1
d
x1
c
x1
b
b
b
x1
d
x1
true
a
1
1
15444
d
1
1
30888
b
1
1
23166
c
1
1
30888
d
1
1
54052
c
1
1
15445
a
1
1
0
b
1
1
7721
d
x1
c
x1
a
a
a
x1
b
b
x1
c
x1
a
a
x1
b
b
b
x1
c
d
x1
NaTT
certifiable-1.6