class A:
    def __init__(self, txt: str):
        self.q: F = None
        self.y: H = None
        self.z: I = None
        self.v: B = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.p: G = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: H = None
        self.q: F = None
        self.o: D = None
        self.u: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: D = None
        self.u: A = None
        self.o: H = None
        self.p: D = None
        self.y: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.r: G = None
        self.q: H = None
        self.x: F = None
        self.w: B = None
        self.s: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.z: D = None
        self.p: G = None
        self.y: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: H = None
        self.q: F = None
        self.o: D = None
        self.u: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.z: D = None
        self.u: A = None
        self.o: H = None
        self.p: D = None
        self.y: A = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.v: B = None
        self.r: G = None
        self.q: H = None
        self.x: F = None
        self.w: B = None
        self.s: A = None
        self.txt = txt

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

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