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

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

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.y: B = None
        self.r: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: J = None
        self.s: F = None
        self.u: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: C = None
        self.o: F = None
        self.v: J = None
        self.s: G = None
        self.p: C = None
        self.q: E = None
        self.x: F = None
        self.r: I = None
        self.w: C = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.o: E = None
        self.y: B = None
        self.r: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: J = None
        self.s: F = None
        self.u: G = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.z: J = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.u: C = None
        self.o: F = None
        self.v: J = None
        self.s: G = None
        self.p: C = None
        self.q: E = None
        self.x: F = None
        self.r: I = None
        self.w: C = None
        self.txt = txt

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

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

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

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