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

class B:
    def __init__(self, txt: str):
        self.s: H = None
        self.w: H = None
        self.p: H = None
        self.o: G = None
        self.v: I = None
        self.u: E = None
        self.z: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.s: H = None
        self.w: H = None
        self.p: H = None
        self.o: G = None
        self.v: I = None
        self.u: E = None
        self.z: I = None
        self.txt = txt

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

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

class E:
    def __init__(self, txt: str):
        self.v: C = None
        self.txt = txt

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

class G:
    def __init__(self, txt: str):
        self.p: F = None
        self.txt = txt

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

class I:
    def __init__(self, txt: str):
        self.p: E = None
        self.txt = txt

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

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