class A:
    def __init__(self, txt: str):
        self.t: F = None
        self.p: I = None
        self.z: G = None
        self.w: I = None
        self.x: D = None
        self.o: G = None
        self.u: F = None
        self.s: E = None
        self.txt = txt

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: I = None
        self.y: D = None
        self.o: H = None
        self.x: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: B = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.y: H = None
        self.q: D = None
        self.s: B = None
        self.p: G = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.s: D = None
        self.u: I = None
        self.y: D = None
        self.o: H = None
        self.x: I = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.u: B = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.y: H = None
        self.q: D = None
        self.s: B = None
        self.p: G = None
        self.txt = txt

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

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