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

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

class C:
    def __init__(self, txt: str):
        self.s: G = None
        self.o: E = None
        self.w: E = None
        self.p: I = None
        self.v: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: F = None
        self.p: H = None
        self.x: I = None
        self.v: I = None
        self.s: F = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.p: F = None
        self.s: B = None
        self.t: D = None
        self.x: I = None
        self.o: F = None
        self.txt = txt

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

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

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

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

m.u = a
m.w = b
m.r = l
m.x = l
m.q = l
m.z = h
m.t = h
m.v = f
b.p = i
b.r = g
i.s = g
i.o = h
i.w = h
i.p = f
i.v = b
l.z = d
l.u = b
h.o = c
h.s = c
h.p = d
h.x = f
h.v = f
h.w = m
a.r = h
a.p = c
a.o = c
a.s = b
a.t = l
a.x = f
g.w = h
g.u = h
g.q = i
g.s = c
g.r = m
g.z = m
g.x = d
g.y = f
d.o = b
d.y = f
d.s = f
f.p = m
f.s = m
f.q = i
f.z = b
f.v = c
f.x = g
f.u = h
c.r = h
c.p = a
c.o = a
c.s = b
c.t = l
c.x = f
assert a.t.u.p.v.txt == "
class A:
    def __init__(self, txt: str):
        self.u: F = None
        self.w: B = None
        self.r: D = None
        self.x: D = None
        self.z: E = None
        self.v: I = None
        self.t: E = None
        self.q: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: G = None
        self.o: E = None
        self.w: E = None
        self.p: I = None
        self.v: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.o: F = None
        self.p: H = None
        self.x: I = None
        self.v: I = None
        self.s: F = None
        self.w: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.r: E = None
        self.p: F = None
        self.s: B = None
        self.t: D = None
        self.x: I = None
        self.o: F = None
        self.txt = txt

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

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

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

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

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