class A:
    def __init__(self, txt: str):
        self.s: I = None
        self.q: G = None
        self.v: F = None
        self.t: D = None
        self.r: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.q: E = None
        self.o: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: E = None
        self.q: B = None
        self.z: F = None
        self.r: A = None
        self.s: H = None
        self.w: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.p: A = None
        self.o: I = None
        self.x: B = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.q: E = None
        self.o: E = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.u: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.v: E = None
        self.q: B = None
        self.z: F = None
        self.r: A = None
        self.s: H = None
        self.w: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.y: A = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.p: A = None
        self.o: I = None
        self.x: B = None
        self.txt = txt

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

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

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