class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.z: B = None
        self.q: I = None
        self.x: I = None
        self.y: A = None
        self.s: C = None
        self.t: I = None
        self.w: H = None
        self.p: I = None
        self.o: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.z: D = None
        self.w: B = None
        self.r: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: E = None
        self.u: H = None
        self.s: I = None
        self.w: I = None
        self.r: B = None
        self.p: B = None
        self.y: A = None
        self.z: B = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.o: E = None
        self.y: D = None
        self.r: F = None
        self.p: B = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.z: B = None
        self.q: I = None
        self.x: I = None
        self.y: A = None
        self.s: C = None
        self.t: I = None
        self.w: H = None
        self.p: I = None
        self.o: F = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: A = None
        self.z: D = None
        self.w: B = None
        self.r: F = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.o: E = None
        self.u: H = None
        self.s: I = None
        self.w: I = None
        self.r: B = None
        self.p: B = None
        self.y: A = None
        self.z: B = None
        self.txt = txt

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

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

class J:
    def __init__(self, txt: str):
        self.o: E = None
        self.y: D = None
        self.r: F = None
        self.p: B = None
        self.txt = txt

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

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