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

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.x: E = None
        self.v: H = None
        self.o: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.v: C = None
        self.w: G = None
        self.o: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.u: D = None
        self.y: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: F = None
        self.q: A = None
        self.y: E = None
        self.w: H = None
        self.u: E = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.z: I = None
        self.x: E = None
        self.v: H = None
        self.o: G = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.t: B = None
        self.v: C = None
        self.w: G = None
        self.o: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.t: B = None
        self.u: D = None
        self.y: B = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.r: F = None
        self.q: A = None
        self.y: E = None
        self.w: H = None
        self.u: E = None
        self.txt = txt

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

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