class A:
    def __init__(self, txt: str):
        self.y: B = None
        self.txt = txt

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: A = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

i = A("i")
d = B("d")
h = C("h")
k = D("k")
c = E("c")
m = F("m")
g = G("g")
n = H("n")
j = I("j")
a = J("a")

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

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

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: E = None
        self.z: A = None
        self.txt = txt

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

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

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

class J:
    def __init__(self, txt: str):
        self.z: E = None
        self.txt = txt

i = A("i")
d = B("d")
h = C("h")
k = D("k")
c = E("c")
m = F("m")
g = G("g")
n = H("n")
j = I("j")
a = J("a")

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