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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.y: C = None
        self.s: G = None
        self.w: B = None
        self.q: C = None
        self.x: H = None
        self.u: G = None
        self.o: G = None
        self.z: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: G = None
        self.y: H = None
        self.r: H = None
        self.p: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: J = None
        self.txt = txt

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

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.t: C = None
        self.y: C = None
        self.s: G = None
        self.w: B = None
        self.q: C = None
        self.x: H = None
        self.u: G = None
        self.o: G = None
        self.z: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: G = None
        self.y: H = None
        self.r: H = None
        self.p: H = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.y: J = None
        self.txt = txt

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

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

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

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

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