class A:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.w: H = None
        self.y: H = None
        self.z: D = None
        self.x: A = None
        self.r: I = None
        self.o: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: I = None
        self.r: J = None
        self.v: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.z: J = None
        self.x: A = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.u: B = None
        self.w: F = None
        self.y: D = None
        self.x: G = None
        self.p: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: I = None
        self.o: J = None
        self.x: H = None
        self.u: C = None
        self.w: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.w: I = None
        self.u: C = None
        self.y: I = None
        self.v: J = None
        self.r: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.s: A = None
        self.x: J = None
        self.v: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: B = None
        self.x: C = None
        self.v: G = None
        self.u: E = None
        self.w: C = None
        self.p: J = None
        self.r: E = None
        self.y: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: G = None
        self.r: B = None
        self.t: G = None
        self.txt = txt

c = A("c")
i = B("i")
a = C("a")
e = D("e")
j = E("j")
b = F("b")
h = G("h")
l = H("l")
m = I("m")
n = J("n")

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

class B:
    def __init__(self, txt: str):
        self.q: H = None
        self.w: H = None
        self.y: H = None
        self.z: D = None
        self.x: A = None
        self.r: I = None
        self.o: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: I = None
        self.r: J = None
        self.v: I = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.y: A = None
        self.z: J = None
        self.x: A = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.q: I = None
        self.u: B = None
        self.w: F = None
        self.y: D = None
        self.x: G = None
        self.p: J = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.v: I = None
        self.o: J = None
        self.x: H = None
        self.u: C = None
        self.w: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: I = None
        self.w: I = None
        self.u: C = None
        self.y: I = None
        self.v: J = None
        self.r: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: E = None
        self.s: A = None
        self.x: J = None
        self.v: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: B = None
        self.x: C = None
        self.v: G = None
        self.u: E = None
        self.w: C = None
        self.p: J = None
        self.r: E = None
        self.y: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.o: G = None
        self.r: B = None
        self.t: G = None
        self.txt = txt

c = A("c")
i = B("i")
a = C("a")
e = D("e")
j = E("j")
b = F("b")
h = G("h")
l = H("l")
m = I("m")
n = J("n")

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