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

class B:
    def __init__(self, txt: str):
        self.q: A = None
        self.t: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.q: H = None
        self.y: B = None
        self.r: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.s: B = None
        self.r: G = None
        self.q: H = None
        self.t: C = None
        self.u: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.y: A = None
        self.txt = txt

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

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

class B:
    def __init__(self, txt: str):
        self.q: A = None
        self.t: G = None
        self.txt = txt

class C:
    def __init__(self, txt: str):
        self.p: G = None
        self.q: H = None
        self.y: B = None
        self.r: F = None
        self.txt = txt

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

class E:
    def __init__(self, txt: str):
        self.x: D = None
        self.s: B = None
        self.r: G = None
        self.q: H = None
        self.t: C = None
        self.u: C = None
        self.txt = txt

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

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

class H:
    def __init__(self, txt: str):
        self.u: G = None
        self.y: A = None
        self.txt = txt

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

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