class A:
    def __init__(self, txt: str):
        self.s: C = None
        self.u: C = None
        self.p: E = None
        self.w: D = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.u: D = None
        self.z: C = None
        self.s: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.x: E = None
        self.y: I = None
        self.t: A = None
        self.p: I = None
        self.v: B = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: D = None
        self.v: F = None
        self.y: D = None
        self.p: E = None
        self.s: I = None
        self.txt = txt

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

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.u: D = None
        self.z: C = None
        self.s: G = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.s: D = None
        self.x: E = None
        self.y: I = None
        self.t: A = None
        self.p: I = None
        self.v: B = None
        self.u: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.r: D = None
        self.v: F = None
        self.y: D = None
        self.p: E = None
        self.s: I = None
        self.txt = txt

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

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

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