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

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

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

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

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

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

j = A("j")
e = B("e")
f = C("f")
c = D("c")
l = E("l")
i = F("i")
n = B("n")
k = F("k")
m = A("m")

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

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

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

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

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

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

j = A("j")
e = B("e")
f = C("f")
c = D("c")
l = E("l")
i = F("i")
n = B("n")
k = F("k")
m = A("m")

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