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

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

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

class D:
    def __init__(self, txt: str):
        self.p: I = None
        self.u: I = None
        self.r: E = None
        self.v: I = None
        self.q: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: G = None
        self.z: I = None
        self.y: A = None
        self.s: C = None
        self.q: I = None
        self.o: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: E = None
        self.s: B = None
        self.v: H = None
        self.r: C = None
        self.txt = txt

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

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

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

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

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

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

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

class D:
    def __init__(self, txt: str):
        self.p: I = None
        self.u: I = None
        self.r: E = None
        self.v: I = None
        self.q: D = None
        self.txt = txt

class E:
    def __init__(self, txt: str):
        self.r: G = None
        self.w: G = None
        self.z: I = None
        self.y: A = None
        self.s: C = None
        self.q: I = None
        self.o: B = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.q: E = None
        self.s: B = None
        self.v: H = None
        self.r: C = None
        self.txt = txt

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

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

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

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

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