class A:
    def __init__(self, txt: str):
        self.s: I = None
        self.q: I = None
        self.t: D = None
        self.z: F = None
        self.o: H = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.t: B = None
        self.u: G = None
        self.r: G = None
        self.z: I = None
        self.y: H = None
        self.v: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: B = None
        self.r: B = None
        self.w: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.v: B = None
        self.u: D = None
        self.x: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.z: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: E = None
        self.t: B = None
        self.u: G = None
        self.r: G = None
        self.z: I = None
        self.y: H = None
        self.v: H = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.q: B = None
        self.r: B = None
        self.w: G = None
        self.txt = txt

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

class F:
    def __init__(self, txt: str):
        self.y: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.v: B = None
        self.u: D = None
        self.x: H = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.v: E = None
        self.z: D = None
        self.txt = txt

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

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