class A:
    def __init__(self, txt: str):
        self.s: I = None
        self.t: H = None
        self.p: G = None
        self.v: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: H = None
        self.w: G = None
        self.t: E = None
        self.z: A = None
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: H = None
        self.r: D = None
        self.p: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: C = None
        self.q: G = None
        self.z: H = None
        self.x: C = None
        self.u: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: C = None
        self.u: F = None
        self.s: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: I = None
        self.s: I = None
        self.u: C = None
        self.q: E = None
        self.w: H = None
        self.p: I = None
        self.x: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: C = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.x: G = None
        self.s: H = None
        self.w: G = None
        self.t: E = None
        self.z: A = None
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: H = None
        self.r: D = None
        self.p: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.w: C = None
        self.q: G = None
        self.z: H = None
        self.x: C = None
        self.u: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: C = None
        self.t: C = None
        self.u: F = None
        self.s: F = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: I = None
        self.s: I = None
        self.u: C = None
        self.q: E = None
        self.w: H = None
        self.p: I = None
        self.x: F = None
        self.txt = txt

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

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