import copy
L = 128
class S:
    u: list[list[int]]
    def __init__(self, num = None):
        self.u = []
        if num is not None:
            self.u = [None] * L
            for w in range(L):
                if num&(1<<w):
                    self.u[w] = 1<<128
                else:
                    self.u[w] = 0
    def __and__(self, num):
        p = copy.deepcopy(self)
        for w in range(L):
            if num&(1<<w):
                pass
            else:
                p.u[w] = 0
        return p
    def __rand__(self, num):
        return self.__and__(num)
    def __or__(self, num):
        p = copy.deepcopy(self)
        for w in range(L):
            if num&(1<<w):
                p.u[w] = 1<<128
        return p
    def __ror__(self, num):
        return self.__or__(num)
    def __xor__(self, num):
        p = copy.deepcopy(self)
        if type(num) != S:
            num = S(num)
        for w in range(L):
            p.u[w] = p.u[w]^num.u[w]
        return p
    def __rxor__(self, num):
        return self.__xor__(num)
    def __lshift__(self, x):
        p = S(0)
        for w in range(L):
            if w+x<L: p.u[w+x]=self.u[w]
        return p
    def __rshift__(self, x):
        p = S(0)
        for w in range(L):
            if w-x>=0: p.u[w-x]=self.u[w]
        return p
    def __invert__(self):
        p = copy.deepcopy(self)
        for w in range(L):
            p.u[w]^=1<<128
        return p
    
def X():
    u = S()
    for w in range(L):
        u.u.append(1<<w)
    return u

x_ = X()
x0 = copy.deepcopy(x_)
def FIXX(W):
    if type(W)!=S:
        W = S(W)
    return W
while True:
    try:
        U = input()
        U = U.strip()
        assert U!=''
    except:
        break
    U = U.split(' ')
    UP = []
    for SS in range(len(U)):
        if (not any('0'<=P<='9' for P in U[SS])) and any('a'<=P<='z' for P in U[SS]):
            U[SS] = U[SS]+'_'
            UP.append(U[SS])
    U = ' '.join(U)
    while True:
        try:
            exec(U)
        except NameError as e:
            try:
                exec(f'{e.name} = 0')
            except:
                pass
            continue
        break
    LL = UP[0]
    exec(f'{LL} = FIXX({LL})')
x = x0^x_   # make sure it's zero!
xx = copy.deepcopy(x)
S = 0
R = [0] * 128 + [1]
for i in range(L):
    J = -1
    ii = 1<<i
    for j in range(S,L):
        if x.u[j]&ii:
            J=j
            break
    if J == -1:
        continue
    if J != S:
        x.u[J],x.u[S] = x.u[S],x.u[J]
    for u in range(0,L):
        if u!=S and (x.u[u]&ii):
            x.u[u] = x.u[u]^x.u[S]
    S += 1
for i in range(L):
    if not (x.u[i]&(1<<L)):
        continue
    out = -1
    for j in range(L):
        if x.u[i]&(1<<j):
            out = j
            break
    R[out] = 1
#print(x.u)
bad = 0
for a in xx.u:
    ss = 0
    for i,u in enumerate(R):
        if u:
            ss += (a>>i)&1
    if ss%2:
        bad = 1
if bad:
    print(':(')
else:
    ans = 0
    for u in range(L):
        if R[u]: ans|=1<<u
    print('0x{:x}'.format(ans))