a
b
a
a
a
a
a
a
x1
a
a
a
a
a
a
a
b
a
a
a
b
x1
2.2
a
b
a
a
a
a
a
a
x1
a
a
a
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
a
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
a
b
a
a
a
b
x1
true
a
b
a
a
a
a
a
a
x1
a
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
a
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
b
x1
a
b
a
a
a
a
a
a
x1
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
a
a
a
b
a
a
a
b
x1
true
a
1
2438
b
1
2439
a
1
1
0
a
b
a
a
a
a
a
a
x1
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
b
x1
a
b
a
a
a
a
a
a
x1
a
a
a
a
a
a
a
b
a
a
a
b
x1
a
b
a
a
a
a
a
a
x1
a
b
x1
a
b
a
a
a
a
a
a
x1
a
b
a
a
a
b
x1
true
Failed!
NaTT
certifiable-1.6