class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: E = None
        self.q: H = None
        self.s: F = None
        self.p: G = None
        self.o: E = None
        self.t: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.y: D = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: E = None
        self.t: F = None
        self.o: J = None
        self.y: H = None
        self.u: D = None
        self.r: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: B = None
        self.z: J = None
        self.u: G = None
        self.x: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.r: E = None
        self.q: D = None
        self.w: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.z: E = None
        self.x: E = None
        self.p: J = None
        self.u: D = None
        self.s: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.z: E = None
        self.v: F = None
        self.q: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: B = None
        self.r: F = None
        self.v: B = None
        self.txt = txt

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

j.y = c
j.u = i
j.o = i
j.q = n
j.s = g
j.p = k
j.t = h
l.x = n
l.y = c
l.p = g
b.v = i
b.t = g
b.o = h
b.r = h
b.y = n
b.u = c
c.w = l
c.o = l
c.x = l
c.z = h
c.u = k
i.q = j
i.u = j
i.v = h
i.y = g
i.o = g
i.x = c
i.t = b
i.w = n
i.z = e
g.y = i
g.r = i
g.q = c
g.w = n
k.w = i
k.x = j
k.y = j
k.u = e
k.t = c
k.p = c
k.z = b
k.q = g
n.z = i
n.x = i
n.s = i
n.p = h
n.u = c
e.s = l
e.z = i
e.q = i
e.v = g
h.w = l
h.v = l
h.r = g
assert c.z.r.r.w.u.txt == "
class A:
    def __init__(self, txt: str):
        self.y: D = None
        self.u: E = None
        self.q: H = None
        self.s: F = None
        self.p: G = None
        self.o: E = None
        self.t: J = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: H = None
        self.y: D = None
        self.p: F = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: E = None
        self.t: F = None
        self.o: J = None
        self.y: H = None
        self.u: D = None
        self.r: J = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.w: B = None
        self.o: B = None
        self.z: J = None
        self.u: G = None
        self.x: B = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: E = None
        self.r: E = None
        self.q: D = None
        self.w: H = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.z: E = None
        self.x: E = None
        self.p: J = None
        self.u: D = None
        self.s: E = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: B = None
        self.z: E = None
        self.v: F = None
        self.q: E = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.w: B = None
        self.r: F = None
        self.v: B = None
        self.txt = txt

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

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