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

class B:
    def __init__(self, txt: str):
        self.y: D = None
        self.s: B = None
        self.x: B = None
        self.u: D = None
        self.p: B = None
        self.v: F = None
        self.q: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.o: G = None
        self.t: E = None
        self.p: F = None
        self.r: B = None
        self.txt = txt

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

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

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

c = A("c")
m = B("m")
d = C("d")
k = D("k")
l = E("l")
h = F("h")
e = G("e")
a = E("a")
j = G("j")
b = B("b")

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

class B:
    def __init__(self, txt: str):
        self.y: D = None
        self.s: B = None
        self.x: B = None
        self.u: D = None
        self.p: B = None
        self.v: F = None
        self.q: F = None
        self.txt = txt

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

class D:
    def __init__(self, txt: str):
        self.u: F = None
        self.o: G = None
        self.t: E = None
        self.p: F = None
        self.r: B = None
        self.txt = txt

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

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

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

c = A("c")
m = B("m")
d = C("d")
k = D("k")
l = E("l")
h = F("h")
e = G("e")
a = E("a")
j = G("j")
b = B("b")

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