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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.z: G = None
        self.s: C = None
        self.p: C = None
        self.w: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.o: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: D = None
        self.v: F = None
        self.w: A = None
        self.txt = txt

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

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

j = A("j")
m = B("m")
f = C("f")
d = D("d")
g = E("g")
b = F("b")
k = G("k")
l = G("l")
i = F("i")
n = D("n")

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

class B:
    def __init__(self, txt: str):
        self.u: E = None
        self.z: G = None
        self.s: C = None
        self.p: C = None
        self.w: E = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.v: C = None
        self.o: G = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.p: D = None
        self.z: D = None
        self.v: F = None
        self.w: A = None
        self.txt = txt

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

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

j = A("j")
m = B("m")
f = C("f")
d = D("d")
g = E("g")
b = F("b")
k = G("k")
l = G("l")
i = F("i")
n = D("n")

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