class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.t: C = None
        self.u: F = None
        self.o: G = None
        self.q: F = None
        self.p: E = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.u: D = None
        self.s: A = None
        self.o: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: C = None
        self.z: E = None
        self.x: E = None
        self.w: B = None
        self.s: B = None
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: G = None
        self.p: D = None
        self.q: A = None
        self.y: F = None
        self.x: G = None
        self.z: D = None
        self.s: B = None
        self.txt = txt

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

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

j = A("j")
d = B("d")
b = C("b")
h = D("h")
i = E("i")
f = F("f")
l = G("l")
c = B("c")

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

class B:
    def __init__(self, txt: str):
        self.r: C = None
        self.u: D = None
        self.s: A = None
        self.o: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: C = None
        self.z: E = None
        self.x: E = None
        self.w: B = None
        self.s: B = None
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: G = None
        self.p: D = None
        self.q: A = None
        self.y: F = None
        self.x: G = None
        self.z: D = None
        self.s: B = None
        self.txt = txt

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

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

j = A("j")
d = B("d")
b = C("b")
h = D("h")
i = E("i")
f = F("f")
l = G("l")
c = B("c")

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