c
c
c
c
x1
b
b
b
b
x1
b
b
x1
x1
b
b
x1
c
b
c
x1
2.2
b
b
x1
b
c
x1
c
c
c
c
x1
b
b
x1
c
c
c
c
x1
b
x1
c
c
c
c
x1
b
b
b
x1
b
b
x1
c
x1
b
b
x1
c
b
c
x1
c
c
c
c
x1
b
b
b
b
x1
true
c
c
c
c
x1
b
b
b
b
x1
b
b
x1
c
b
c
x1
b
b
x1
c
x1
c
c
c
c
x1
b
b
x1
c
c
c
c
x1
b
b
b
x1
c
c
c
c
x1
b
x1
b
b
x1
b
c
x1
true
Failed!
NaTT
certifiable-1.6