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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: C = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.z: D = None
        self.o: G = None
        self.q: G = None
        self.s: F = None
        self.txt = txt

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

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

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

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

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

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

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

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

class H:
    def __init__(self, txt: str):
        self.o: D = None
        self.p: C = None
        self.txt = txt

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

class J:
    def __init__(self, txt: str):
        self.p: F = None
        self.z: D = None
        self.o: G = None
        self.q: G = None
        self.s: F = None
        self.txt = txt

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

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