class A:
    def __init__(self, txt: str):
        self.p: D = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: J = None
        self.u: I = None
        self.w: G = None
        self.p: B = None
        self.v: D = None
        self.y: J = None
        self.t: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.v: C = None
        self.z: I = None
        self.q: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: J = None
        self.y: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: B = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: D = None
        self.o: J = None
        self.u: I = None
        self.w: G = None
        self.p: B = None
        self.v: D = None
        self.y: J = None
        self.t: B = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: H = None
        self.v: C = None
        self.z: I = None
        self.q: A = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.q: J = None
        self.y: D = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.s: C = None
        self.w: B = None
        self.txt = txt

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

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

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

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