class A:
    def __init__(self, txt: str):
        self.x: F = None
        self.y: I = None
        self.w: E = None
        self.v: F = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.u: E = None
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.v: A = None
        self.s: I = None
        self.r: A = None
        self.o: E = None
        self.w: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: G = None
        self.z: B = None
        self.s: A = None
        self.w: D = None
        self.u: E = None
        self.t: D = None
        self.q: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: D = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.v: G = None
        self.u: E = None
        self.q: D = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.t: F = None
        self.v: A = None
        self.s: I = None
        self.r: A = None
        self.o: E = None
        self.w: D = None
        self.txt = txt

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

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

class F:
    def __init__(self, txt: str):
        self.p: G = None
        self.z: B = None
        self.s: A = None
        self.w: D = None
        self.u: E = None
        self.t: D = None
        self.q: I = None
        self.txt = txt

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

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

class I:
    def __init__(self, txt: str):
        self.v: D = None
        self.txt = txt

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

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