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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.o: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: F = None
        self.p: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.p: B = None
        self.v: F = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: F = None
        self.v: H = None
        self.y: C = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: G = None
        self.o: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.r: F = None
        self.w: F = None
        self.p: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: D = None
        self.p: B = None
        self.v: F = None
        self.txt = txt

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

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

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

class I:
    def __init__(self, txt: str):
        self.o: F = None
        self.q: F = None
        self.v: H = None
        self.y: C = None
        self.txt = txt

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

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