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

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

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: D = None
        self.t: G = None
        self.r: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.s: G = None
        self.v: E = None
        self.t: D = None
        self.x: E = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.u: F = None
        self.t: B = None
        self.s: E = None
        self.o: F = None
        self.y: D = None
        self.txt = txt

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

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

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

class C:
    def __init__(self, txt: str):
        self.y: D = None
        self.o: D = None
        self.t: G = None
        self.r: A = None
        self.txt = txt

class D:
    def __init__(self, txt: str):
        self.q: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.u: G = None
        self.s: G = None
        self.v: E = None
        self.t: D = None
        self.x: E = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: B = None
        self.u: F = None
        self.t: B = None
        self.s: E = None
        self.o: F = None
        self.y: D = None
        self.txt = txt

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

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