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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.o: H = None
        self.x: E = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.u: D = None
        self.t: E = None
        self.p: F = None
        self.txt = txt

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

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

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

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

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

class C:
    def __init__(self, txt: str):
        self.u: E = None
        self.o: H = None
        self.x: E = None
        self.txt = txt

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

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

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

class G:
    def __init__(self, txt: str):
        self.z: E = None
        self.u: D = None
        self.t: E = None
        self.p: F = None
        self.txt = txt

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

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

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

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