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

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.v: F = None
        self.r: I = None
        self.w: C = None
        self.t: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.v: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: I = None
        self.s: I = None
        self.u: I = None
        self.q: F = None
        self.z: F = None
        self.x: H = None
        self.p: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.q: D = None
        self.y: H = None
        self.u: E = None
        self.t: D = None
        self.w: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: A = None
        self.o: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: I = None
        self.s: G = None
        self.w: I = None
        self.o: A = None
        self.txt = txt

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

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

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

class B:
    def __init__(self, txt: str):
        self.z: A = None
        self.v: F = None
        self.r: I = None
        self.w: C = None
        self.t: I = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.s: A = None
        self.v: B = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.y: I = None
        self.s: I = None
        self.u: I = None
        self.q: F = None
        self.z: F = None
        self.x: H = None
        self.p: F = None
        self.txt = txt

class F:
    def __init__(self, txt: str):
        self.o: G = None
        self.q: D = None
        self.y: H = None
        self.u: E = None
        self.t: D = None
        self.w: D = None
        self.txt = txt

class G:
    def __init__(self, txt: str):
        self.x: A = None
        self.o: A = None
        self.txt = txt

class H:
    def __init__(self, txt: str):
        self.t: I = None
        self.s: G = None
        self.w: I = None
        self.o: A = None
        self.txt = txt

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

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

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