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

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

class C:
    def __init__(self, txt: str):
        self.s: H = None
        self.q: A = None
        self.r: G = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: J = None
        self.r: A = None
        self.w: G = None
        self.p: G = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.y: A = None
        self.v: B = None
        self.u: C = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.s: H = None
        self.q: A = None
        self.r: G = None
        self.txt = txt

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: J = None
        self.r: A = None
        self.w: G = None
        self.p: G = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.y: A = None
        self.v: B = None
        self.u: C = None
        self.txt = txt

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

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