a
a
a
x1
b
b
x1
b
b
b
x1
c
x1
c
x1
d
d
x1
d
x1
a
a
x1
2.2
c
x1
d
d
x1
d
x1
a
a
x1
d
x1
a
x1
a
a
a
x1
b
x1
c
x1
d
x1
b
b
b
x1
c
x1
a
a
a
x1
b
b
x1
true
a
a
a
x1
b
b
x1
b
b
b
x1
c
x1
c
x1
d
x1
d
x1
a
a
x1
a
a
a
x1
b
x1
d
x1
a
x1
c
x1
d
d
x1
true
a
1
1
15446
d
1
1
30892
b
1
1
23169
c
1
1
61784
d
1
1
15447
c
1
1
54059
a
1
1
0
b
1
1
7722
d
x1
a
a
x1
a
a
a
x1
b
b
x1
c
x1
d
d
x1
b
b
b
x1
c
x1
NaTT
certifiable-1.6