a
b
x
b
a
a
x
b
c
x
c
b
b
x
c
a
x
a
c
c
x
u
a
x
x
v
b
x
x
w
c
x
x
a
u
x
x
b
v
x
x
c
w
x
x
2.2
b
c
x
b
b
x
c
a
x
c
x
a
b
x
a
x
a
b
x
b
a
a
x
c
a
x
c
c
x
b
c
x
b
x
b
c
x
c
b
b
x
a
b
x
a
a
x
c
a
x
a
c
c
x
true
c
a
x
a
c
c
x
a
b
x
a
a
x
b
c
x
c
b
b
x
b
c
x
b
x
a
b
x
a
x
c
a
x
c
x
c
a
x
c
c
x
a
b
x
b
a
a
x
b
c
x
b
b
x
true
b
1
1
b
1
1
a
1
0
v
1
0
w
1
0
u
1
0
u
1
0
w
1
0
c
1
3
1
v
1
0
c
1
2
a
1
1
a
1
1
0
v
1
1
1
w
1
1
u
1
1
10451
u
1
1
w
1
1
30613
c
1
1
0
v
1
1
c
1
1
0
a
1
1
0
c
a
x
c
c
x
c
a
x
c
x
a
b
x
a
x
a
b
x
a
a
x
b
v
x
x
a
b
x
b
a
a
x
c
a
x
a
c
c
x
a
u
x
x
c
w
x
x
b
c
x
c
b
b
x
a
b
x
a
x
a
b
x
a
a
x
true
a
1
1
b
1
1
v
1
0
w
1
0
b
1
3
1
u
1
0
u
1
0
w
1
0
1
c
1
3
v
1
0
c
1
2
a
1
1
1
v
1
1
1
w
1
1
b
1
1
0
u
1
1
28101
u
1
1
w
1
1
1143
c
1
1
0
v
1
1
c
1
1
0
a
1
1
0
b
v
x
x
a
b
x
b
a
a
x
c
a
x
a
c
c
x
a
u
x
x
c
w
x
x
b
c
x
c
b
b
x
c
a
x
c
x
c
a
x
c
c
x
true
c
1
1
c
1
1
b
1
1
a
1
4
1
v
1
0
w
1
0
b
1
2
u
1
0
u
1
0
w
1
0
1
v
1
0
a
1
1
1
a
1
1
0
v
1
1
1
w
1
1
b
1
1
0
u
1
1
28101
u
1
1
w
1
1
20538
v
1
1
a
1
1
0
b
v
x
x
a
b
x
b
a
a
x
c
a
x
a
c
c
x
a
u
x
x
c
w
x
x
b
c
x
c
b
b
x
NaTT
certifiable-1.6