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

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

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

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

class E:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: B = None
        self.u: C = None
        self.w: D = None
        self.x: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.q: H = None
        self.p: I = None
        self.x: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: A = None
        self.u: H = None
        self.q: C = None
        self.x: I = None
        self.z: I = None
        self.s: I = None
        self.o: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.t: C = None
        self.x: B = None
        self.txt = txt

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

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

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

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

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

class E:
    def __init__(self, txt: str):
        self.z: I = None
        self.o: B = None
        self.u: C = None
        self.w: D = None
        self.x: C = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.y: H = None
        self.q: H = None
        self.p: I = None
        self.x: B = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: H = None
        self.w: A = None
        self.u: H = None
        self.q: C = None
        self.x: I = None
        self.z: I = None
        self.s: I = None
        self.o: F = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.v: E = None
        self.y: C = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.s: F = None
        self.t: C = None
        self.x: B = None
        self.txt = txt

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

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