class A:
    def __init__(self, txt: str):
        self.z: B = None
        self.s: G = None
        self.o: F = None
        self.u: H = None
        self.t: F = None
        self.x: E = None
        self.w: B = None
        self.p: C = None
        self.r: G = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: F = None
        self.x: C = None
        self.r: I = None
        self.v: I = None
        self.w: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: I = None
        self.t: E = None
        self.txt = txt

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

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.z: C = None
        self.u: F = None
        self.x: C = None
        self.r: I = None
        self.v: I = None
        self.w: I = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: I = None
        self.t: E = None
        self.txt = txt

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

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

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

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

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