class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.v: F = None
        self.y: B = None
        self.z: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: C = None
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.o: E = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.p: F = None
        self.x: D = None
        self.z: A = None
        self.y: E = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.z: A = None
        self.o: C = None
        self.v: E = None
        self.txt = txt

g = A("g")
l = B("l")
n = C("n")
i = D("i")
b = E("b")
f = F("f")
m = C("m")
h = F("h")
a = E("a")

g.u = l
g.y = l
g.z = l
g.v = h
l.t = i
n.p = m
n.x = g
i.r = b
i.o = b
i.q = m
b.t = g
b.z = g
b.w = g
b.p = f
b.x = i
b.y = a
f.q = i
f.z = g
f.o = m
f.v = b
m.p = n
m.x = g
h.q = i
h.z = g
h.o = n
h.v = b
a.t = g
a.z = g
a.w = g
a.p = h
a.x = i
a.y = b
assert n.p.x.v.txt == "
class A:
    def __init__(self, txt: str):
        self.u: B = None
        self.v: F = None
        self.y: B = None
        self.z: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: C = None
        self.x: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: E = None
        self.o: E = None
        self.q: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.t: A = None
        self.p: F = None
        self.x: D = None
        self.z: A = None
        self.y: E = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: D = None
        self.z: A = None
        self.o: C = None
        self.v: E = None
        self.txt = txt

g = A("g")
l = B("l")
n = C("n")
i = D("i")
b = E("b")
f = F("f")
m = C("m")
h = F("h")
a = E("a")

g.u = l
g.y = l
g.z = l
g.v = h
l.t = i
n.p = m
n.x = g
i.r = b
i.o = b
i.q = m
b.t = g
b.z = g
b.w = g
b.p = f
b.x = i
b.y = a
f.q = i
f.z = g
f.o = m
f.v = b
m.p = n
m.x = g
h.q = i
h.z = g
h.o = n
h.v = b
a.t = g
a.z = g
a.w = g
a.p = h
a.x = i
a.y = b
assert n.p.x.v.txt == "h"