class A:
    def __init__(self, txt: str):
        self.u: G = None
        self.p: H = None
        self.t: B = None
        self.txt = txt

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: F = None
        self.u: H = None
        self.o: C = None
        self.v: G = None
        self.z: C = None
        self.t: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: A = None
        self.z: D = None
        self.y: D = None
        self.o: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.q: C = None
        self.s: F = None
        self.y: I = None
        self.x: C = None
        self.txt = txt

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.x: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.r: A = None
        self.w: F = None
        self.u: H = None
        self.o: C = None
        self.v: G = None
        self.z: C = None
        self.t: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.s: A = None
        self.z: D = None
        self.y: D = None
        self.o: E = None
        self.txt = txt

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

class H:
    def __init__(self, txt: str):
        self.q: C = None
        self.s: F = None
        self.y: I = None
        self.x: C = None
        self.txt = txt

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

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

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