class A:
    def __init__(self, txt: str):
        self.p: G = None
        self.v: H = None
        self.x: F = None
        self.u: H = None
        self.w: F = None
        self.t: F = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: I = None
        self.s: E = None
        self.t: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: C = None
        self.p: H = None
        self.r: B = None
        self.s: B = None
        self.q: H = None
        self.t: C = None
        self.w: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: B = None
        self.r: I = None
        self.o: D = None
        self.z: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: I = None
        self.v: E = None
        self.y: E = None
        self.u: F = None
        self.w: D = None
        self.x: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: G = None
        self.w: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.u: I = None
        self.s: E = None
        self.t: E = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: B = None
        self.y: C = None
        self.p: H = None
        self.r: B = None
        self.s: B = None
        self.q: H = None
        self.t: C = None
        self.w: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: B = None
        self.r: I = None
        self.o: D = None
        self.z: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: E = None
        self.o: I = None
        self.v: E = None
        self.y: E = None
        self.u: F = None
        self.w: D = None
        self.x: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.s: G = None
        self.w: C = None
        self.txt = txt

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

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