class A:
    def __init__(self, txt: str):
        self.r: H = None
        self.t: C = None
        self.w: G = None
        self.u: I = None
        self.s: E = None
        self.z: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.o: C = None
        self.z: I = None
        self.x: G = None
        self.s: J = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: G = None
        self.z: I = None
        self.o: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.z: A = None
        self.q: A = None
        self.t: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: A = None
        self.z: B = None
        self.s: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: F = None
        self.u: J = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.u: F = None
        self.o: C = None
        self.z: I = None
        self.x: G = None
        self.s: J = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: G = None
        self.z: I = None
        self.o: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: D = None
        self.z: A = None
        self.q: A = None
        self.t: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: A = None
        self.z: B = None
        self.s: G = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.v: F = None
        self.u: J = None
        self.txt = txt

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

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

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