class A:
    def __init__(self, txt: str):
        self.x: D = None
        self.q: H = None
        self.u: B = None
        self.w: C = None
        self.y: I = None
        self.v: G = None
        self.z: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: G = None
        self.x: D = None
        self.y: A = None
        self.q: A = None
        self.z: F = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.q: A = None
        self.t: G = None
        self.v: G = None
        self.y: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.s: A = None
        self.o: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: H = None
        self.y: C = None
        self.v: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.w: G = None
        self.x: D = None
        self.y: A = None
        self.q: A = None
        self.z: F = None
        self.p: H = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.q: A = None
        self.t: G = None
        self.v: G = None
        self.y: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.t: I = None
        self.s: A = None
        self.o: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.u: B = None
        self.z: H = None
        self.y: C = None
        self.v: C = None
        self.txt = txt

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

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