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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.y: C = None
        self.p: E = None
        self.v: C = None
        self.t: D = None
        self.z: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.u: D = None
        self.q: B = None
        self.x: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.r: G = None
        self.y: B = None
        self.p: C = None
        self.u: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.u: C = None
        self.v: H = None
        self.p: A = None
        self.y: D = None
        self.q: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: E = None
        self.o: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: F = None
        self.w: A = None
        self.p: B = None
        self.o: F = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.s: C = None
        self.y: C = None
        self.p: E = None
        self.v: C = None
        self.t: D = None
        self.z: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.o: G = None
        self.u: D = None
        self.q: B = None
        self.x: G = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.o: A = None
        self.r: G = None
        self.y: B = None
        self.p: C = None
        self.u: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: G = None
        self.u: C = None
        self.v: H = None
        self.p: A = None
        self.y: D = None
        self.q: A = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.t: E = None
        self.r: E = None
        self.o: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.q: F = None
        self.w: A = None
        self.p: B = None
        self.o: F = None
        self.txt = txt

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

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

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