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

class B:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: F = None
        self.s: A = None
        self.r: G = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: J = None
        self.w: D = None
        self.z: I = None
        self.s: A = None
        self.y: C = None
        self.x: A = None
        self.q: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.s: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.r: D = None
        self.p: H = None
        self.q: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.x: J = None
        self.p: F = None
        self.s: A = None
        self.r: G = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.w: B = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.u: J = None
        self.w: D = None
        self.z: I = None
        self.s: A = None
        self.y: C = None
        self.x: A = None
        self.q: J = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.o: C = None
        self.s: D = None
        self.txt = txt

class J:
    def __init__(self, txt: str):
        self.r: D = None
        self.p: H = None
        self.q: D = None
        self.txt = txt

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

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