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

class B:
    def __init__(self, txt: str):
        self.y: I = None
        self.r: E = None
        self.o: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.t: C = None
        self.r: B = None
        self.y: H = None
        self.v: H = None
        self.p: I = None
        self.o: A = None
        self.q: H = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: H = None
        self.s: A = None
        self.y: B = None
        self.o: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.y: I = None
        self.r: E = None
        self.o: G = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: H = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.w: E = None
        self.t: C = None
        self.r: B = None
        self.y: H = None
        self.v: H = None
        self.p: I = None
        self.o: A = None
        self.q: H = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.u: F = None
        self.v: H = None
        self.s: A = None
        self.y: B = None
        self.o: A = None
        self.txt = txt

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

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