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

class B:
    def __init__(self, txt: str):
        self.s: H = None
        self.t: J = None
        self.z: E = None
        self.p: G = None
        self.v: D = None
        self.o: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.v: A = None
        self.s: E = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.z: H = None
        self.v: G = None
        self.x: H = None
        self.r: G = None
        self.t: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: J = None
        self.t: J = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: A = None
        self.v: E = None
        self.q: E = None
        self.t: D = None
        self.w: E = None
        self.txt = txt

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

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: H = None
        self.t: J = None
        self.z: E = None
        self.p: G = None
        self.v: D = None
        self.o: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.v: A = None
        self.s: E = None
        self.t: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.z: H = None
        self.v: G = None
        self.x: H = None
        self.r: G = None
        self.t: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: J = None
        self.t: J = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: A = None
        self.v: E = None
        self.q: E = None
        self.t: D = None
        self.w: E = None
        self.txt = txt

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

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

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

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