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

class B:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: H = None
        self.t: H = None
        self.u: E = None
        self.r: B = None
        self.v: E = None
        self.q: A = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.s: D = None
        self.o: B = None
        self.x: E = None
        self.z: F = None
        self.t: C = None
        self.u: A = None
        self.y: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: H = None
        self.y: E = None
        self.v: A = None
        self.o: C = None
        self.t: H = None
        self.s: E = None
        self.z: G = None
        self.x: G = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: H = None
        self.y: H = None
        self.t: H = None
        self.u: E = None
        self.r: B = None
        self.v: E = None
        self.q: A = None
        self.p: E = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.r: F = None
        self.s: D = None
        self.o: B = None
        self.x: E = None
        self.z: F = None
        self.t: C = None
        self.u: A = None
        self.y: I = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: E = None
        self.w: H = None
        self.y: E = None
        self.v: A = None
        self.o: C = None
        self.t: H = None
        self.s: E = None
        self.z: G = None
        self.x: G = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.r: E = None
        self.txt = txt

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

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

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