class A:
    def __init__(self, txt: str):
        self.z: F = None
        self.y: H = None
        self.o: I = None
        self.p: H = None
        self.q: G = None
        self.w: D = None
        self.t: G = None
        self.txt = txt

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

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

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.p: C = None
        self.y: I = None
        self.q: C = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: H = None
        self.p: I = None
        self.u: C = None
        self.w: A = None
        self.v: G = None
        self.t: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.t: D = None
        self.q: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: I = None
        self.t: B = None
        self.s: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: B = None
        self.y: G = None
        self.txt = txt

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.t: I = None
        self.p: C = None
        self.y: I = None
        self.q: C = None
        self.v: H = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.o: H = None
        self.p: I = None
        self.u: C = None
        self.w: A = None
        self.v: G = None
        self.t: D = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.x: D = None
        self.t: D = None
        self.q: I = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.r: I = None
        self.q: I = None
        self.t: B = None
        self.s: I = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.o: B = None
        self.txt = txt

class I:
    def __init__(self, txt: str):
        self.w: B = None
        self.y: G = None
        self.txt = txt

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

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