class A:
    def __init__(self, txt: str):
        self.o: E = None
        self.v: B = None
        self.y: H = None
        self.w: E = None
        self.p: B = None
        self.r: I = None
        self.q: C = None
        self.z: E = None
        self.x: D = None
        self.txt = txt

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.y: C = None
        self.u: B = None
        self.txt = txt

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

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

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

c = A("c")
h = B("h")
n = C("n")
f = D("f")
k = E("k")
g = F("g")
m = G("m")
i = H("i")
l = I("l")

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

class B:
    def __init__(self, txt: str):
        self.y: E = None
        self.txt = txt

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

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

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

class F:
    def __init__(self, txt: str):
        self.o: A = None
        self.y: C = None
        self.u: B = None
        self.txt = txt

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

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

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

c = A("c")
h = B("h")
n = C("n")
f = D("f")
k = E("k")
g = F("g")
m = G("m")
i = H("i")
l = I("l")

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