class A:
    def __init__(self, txt: str):
        self.z: I = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: H = None
        self.s: C = None
        self.u: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: H = None
        self.s: E = None
        self.o: E = None
        self.p: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.x: E = None
        self.t: H = None
        self.s: C = None
        self.u: A = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.w: E = None
        self.r: H = None
        self.s: E = None
        self.o: E = None
        self.p: H = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.w: E = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.p: G = None
        self.txt = txt

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

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

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