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

class B:
    def __init__(self, txt: str):
        self.z: G = None
        self.w: I = None
        self.r: F = None
        self.o: G = None
        self.q: C = None
        self.s: J = None
        self.p: A = None
        self.v: D = None
        self.y: A = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: I = None
        self.y: H = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.p: I = None
        self.x: F = None
        self.z: A = None
        self.r: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.u: J = None
        self.t: G = None
        self.p: D = None
        self.w: D = None
        self.r: E = None
        self.y: G = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: G = None
        self.w: I = None
        self.r: F = None
        self.o: G = None
        self.q: C = None
        self.s: J = None
        self.p: A = None
        self.v: D = None
        self.y: A = None
        self.u: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.w: I = None
        self.y: H = None
        self.txt = txt

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

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

class G:
    def __init__(self, txt: str):
        self.q: D = None
        self.p: I = None
        self.x: F = None
        self.z: A = None
        self.r: D = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.z: A = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.q: A = None
        self.u: J = None
        self.t: G = None
        self.p: D = None
        self.w: D = None
        self.r: E = None
        self.y: G = None
        self.txt = txt

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

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

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