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

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: B = None
        self.z: E = None
        self.o: A = None
        self.u: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: D = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: F = None
        self.y: F = None
        self.x: G = None
        self.r: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.q: I = None
        self.r: C = None
        self.x: C = None
        self.s: H = None
        self.y: D = None
        self.w: H = None
        self.t: G = None
        self.p: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.u: A = None
        self.z: F = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.r: A = None
        self.q: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.y: B = None
        self.q: B = None
        self.z: E = None
        self.o: A = None
        self.u: H = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.t: E = None
        self.q: D = None
        self.r: C = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: F = None
        self.y: F = None
        self.x: G = None
        self.r: H = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: D = None
        self.q: I = None
        self.r: C = None
        self.x: C = None
        self.s: H = None
        self.y: D = None
        self.w: H = None
        self.t: G = None
        self.p: C = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.u: A = None
        self.z: F = None
        self.txt = txt

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

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