class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: B = None
        self.r: G = None
        self.v: B = None
        self.o: B = None
        self.q: J = None
        self.z: H = None
        self.p: J = None
        self.x: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: G = None
        self.u: A = None
        self.s: J = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: I = None
        self.x: A = None
        self.q: J = None
        self.u: E = None
        self.s: G = None
        self.t: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.p: A = None
        self.t: B = None
        self.v: I = None
        self.r: C = None
        self.u: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: I = None
        self.r: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.x: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: F = None
        self.p: F = None
        self.q: D = None
        self.y: J = None
        self.v: E = None
        self.s: H = None
        self.u: H = None
        self.o: C = None
        self.r: B = None
        self.t: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: E = None
        self.txt = txt

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

l.t = i
l.y = i
l.v = i
l.o = i
l.r = b
l.x = b
l.q = h
l.p = h
l.z = f
i.t = b
i.u = l
i.s = h
i.y = j
n.v = j
n.y = m
n.x = l
n.t = l
n.q = h
n.u = a
n.s = b
j.s = a
j.p = d
j.y = m
j.x = h
j.o = h
a.x = b
a.p = l
a.t = i
a.u = i
a.v = m
a.r = n
d.v = m
d.r = h
b.r = d
b.x = a
f.s = a
f.t = i
m.z = d
m.p = d
m.q = j
m.y = h
m.v = a
m.s = f
m.u = f
m.o = n
m.r = i
m.t = i
h.x = a
assert m.y.x.v.s.t.t.txt == "
class A:
    def __init__(self, txt: str):
        self.t: B = None
        self.y: B = None
        self.r: G = None
        self.v: B = None
        self.o: B = None
        self.q: J = None
        self.z: H = None
        self.p: J = None
        self.x: G = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.t: G = None
        self.u: A = None
        self.s: J = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.v: D = None
        self.y: I = None
        self.x: A = None
        self.q: J = None
        self.u: E = None
        self.s: G = None
        self.t: A = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: G = None
        self.p: A = None
        self.t: B = None
        self.v: I = None
        self.r: C = None
        self.u: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.v: I = None
        self.r: J = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: F = None
        self.x: E = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.z: F = None
        self.p: F = None
        self.q: D = None
        self.y: J = None
        self.v: E = None
        self.s: H = None
        self.u: H = None
        self.o: C = None
        self.r: B = None
        self.t: B = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.x: E = None
        self.txt = txt

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

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