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

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.y: F = None
        self.z: C = None
        self.w: H = None
        self.u: A = None
        self.t: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: A = None
        self.y: E = None
        self.r: B = None
        self.z: F = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: D = None
        self.q: G = None
        self.s: D = None
        self.u: F = None
        self.x: E = None
        self.t: H = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: F = None
        self.y: F = None
        self.z: C = None
        self.w: H = None
        self.u: A = None
        self.t: C = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.x: E = None
        self.w: A = None
        self.y: E = None
        self.r: B = None
        self.z: F = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.y: D = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.z: F = None
        self.w: D = None
        self.q: G = None
        self.s: D = None
        self.u: F = None
        self.x: E = None
        self.t: H = None
        self.txt = txt

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

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