class A:
    def __init__(self, txt: str):
        self.x: B = None
        self.z: B = None
        self.r: C = None
        self.v: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.p: A = None
        self.t: G = None
        self.s: F = None
        self.x: F = None
        self.o: C = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.u: A = None
        self.z: D = None
        self.r: F = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.p: C = None
        self.q: A = None
        self.z: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.s: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: C = None
        self.t: C = None
        self.r: F = None
        self.q: C = None
        self.z: A = None
        self.x: F = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.v: B = None
        self.u: G = None
        self.o: F = None
        self.z: F = None
        self.txt = txt

e = A("e")
j = B("j")
h = C("h")
k = D("k")
f = E("f")
i = F("i")
c = G("c")
l = F("l")
b = G("b")

e.x = j
e.z = j
e.r = h
e.v = c
j.y = b
j.t = b
j.p = e
j.s = i
j.x = i
j.o = h
j.v = l
h.x = f
h.u = e
h.z = k
h.r = l
h.y = c
k.w = j
k.p = h
k.q = e
k.z = f
f.u = b
f.s = k
i.w = h
i.t = h
i.q = h
i.r = l
i.x = l
i.z = e
c.p = h
c.v = j
c.u = b
c.o = l
c.z = i
l.w = h
l.t = h
l.q = h
l.r = i
l.x = i
l.z = e
b.p = h
b.v = j
b.u = c
b.o = i
b.z = l
assert c.o.x.r.txt == "
class A:
    def __init__(self, txt: str):
        self.x: B = None
        self.z: B = None
        self.r: C = None
        self.v: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: G = None
        self.p: A = None
        self.t: G = None
        self.s: F = None
        self.x: F = None
        self.o: C = None
        self.v: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.u: A = None
        self.z: D = None
        self.r: F = None
        self.y: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.p: C = None
        self.q: A = None
        self.z: E = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.s: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: C = None
        self.t: C = None
        self.r: F = None
        self.q: C = None
        self.z: A = None
        self.x: F = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.p: C = None
        self.v: B = None
        self.u: G = None
        self.o: F = None
        self.z: F = None
        self.txt = txt

e = A("e")
j = B("j")
h = C("h")
k = D("k")
f = E("f")
i = F("i")
c = G("c")
l = F("l")
b = G("b")

e.x = j
e.z = j
e.r = h
e.v = c
j.y = b
j.t = b
j.p = e
j.s = i
j.x = i
j.o = h
j.v = l
h.x = f
h.u = e
h.z = k
h.r = l
h.y = c
k.w = j
k.p = h
k.q = e
k.z = f
f.u = b
f.s = k
i.w = h
i.t = h
i.q = h
i.r = l
i.x = l
i.z = e
c.p = h
c.v = j
c.u = b
c.o = l
c.z = i
l.w = h
l.t = h
l.q = h
l.r = i
l.x = i
l.z = e
b.p = h
b.v = j
b.u = c
b.o = i
b.z = l
assert c.o.x.r.txt == "l"