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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.s: E = None
        self.y: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.o: G = None
        self.q: G = None
        self.z: F = None
        self.t: F = None
        self.v: H = None
        self.x: E = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: D = None
        self.txt = txt

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

c = A("c")
j = B("j")
b = C("b")
d = D("d")
f = E("f")
i = F("i")
e = G("e")
n = H("n")
a = I("a")
g = J("g")

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

class B:
    def __init__(self, txt: str):
        self.z: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: I = None
        self.s: E = None
        self.y: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.o: G = None
        self.q: G = None
        self.z: F = None
        self.t: F = None
        self.v: H = None
        self.x: E = None
        self.txt = txt

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

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

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

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

class I:
    def __init__(self, txt: str):
        self.u: D = None
        self.txt = txt

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

c = A("c")
j = B("j")
b = C("b")
d = D("d")
f = E("f")
i = F("i")
e = G("e")
n = H("n")
a = I("a")
g = J("g")

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