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

class B:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: H = None
        self.z: A = None
        self.x: A = None
        self.r: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.z: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.w: H = None
        self.y: F = None
        self.q: A = None
        self.v: D = None
        self.o: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: H = None
        self.x: C = None
        self.q: H = None
        self.w: D = None
        self.p: A = None
        self.txt = txt

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

l = A("l")
h = B("h")
j = C("j")
i = D("i")
a = E("a")
k = F("k")
b = G("b")
c = H("c")
m = A("m")

l.t = k
l.o = j
h.o = k
h.v = c
h.z = l
h.x = l
h.r = i
j.t = l
j.z = i
i.y = m
i.z = m
i.w = j
i.u = b
i.p = c
i.r = c
i.v = l
i.t = h
a.u = h
a.w = c
a.y = k
a.o = k
a.q = l
a.v = i
k.r = j
k.x = i
b.o = c
b.q = c
b.x = j
b.w = i
b.p = l
c.w = b
c.z = b
c.y = b
c.r = h
c.u = h
c.x = h
c.v = m
m.t = k
m.o = j
assert c.u.o.x.v.t.x.u.txt == "
class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.o: C = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.o: F = None
        self.v: H = None
        self.z: A = None
        self.x: A = None
        self.r: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: A = None
        self.z: D = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.u: B = None
        self.w: H = None
        self.y: F = None
        self.q: A = None
        self.v: D = None
        self.o: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: H = None
        self.x: C = None
        self.q: H = None
        self.w: D = None
        self.p: A = None
        self.txt = txt

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

l = A("l")
h = B("h")
j = C("j")
i = D("i")
a = E("a")
k = F("k")
b = G("b")
c = H("c")
m = A("m")

l.t = k
l.o = j
h.o = k
h.v = c
h.z = l
h.x = l
h.r = i
j.t = l
j.z = i
i.y = m
i.z = m
i.w = j
i.u = b
i.p = c
i.r = c
i.v = l
i.t = h
a.u = h
a.w = c
a.y = k
a.o = k
a.q = l
a.v = i
k.r = j
k.x = i
b.o = c
b.q = c
b.x = j
b.w = i
b.p = l
c.w = b
c.z = b
c.y = b
c.r = h
c.u = h
c.x = h
c.v = m
m.t = k
m.o = j
assert c.u.o.x.v.t.x.u.txt == "b"