Buggy python submission (verdict: Runtime Error):
while 1:
    n, m = map(int, input().split())
    if n+m == 0:
        break
    B = [int(input(),2) for i in range(n)]
    C = {0: 0}
    for b in B:
        for k, v in [*C.items()]:
            C[k^b] = max(C.get(k^b, 0), v+1)
    print(C[0])

Fixed submission:
def make(n):
    C = {0: 0}
    for i in range(n):
        b = int(input(), 2)
        for k, v in dict(C).items():
            if C.get(k^b, 0) < v+1:
                C[k^b] = v+1
    return C
def calc(P, Q):
    yield 0
    for k, v in P.items():
        if k in Q:
            yield v + Q[k]
def solve():
    while 1:
        n, m = map(int, input().split())
        if n+m == 0:
            break
        yield max(calc(make(n//2), make(n-n//2)))
print(*solve(), sep="\n")

Buggy python submission (verdict: Runtime Error):
a=65280; b=61680; c=52428; d=43690; e=65535
QS = [[] for i in range(17)]
QS[1] = [a, b, c, d]
L = {a: 1, b: 1, c: 1, d: 1, e: 1, e: 1, 0: 1}
H = []
get = L.get
push = H.append
for l in range(1, 16):
    Q = QS[l]
    li = 13-l; l3 = l+3; l1 = l+1
    pop = Q.pop
    pushQN = QS[l1].append
    while Q:
        p = pop()
        if L[p] < l: continue
        if l < 13:
            if l1 < get(p ^ e, 17):
                L[p ^ e] = l1
                l < 12 and pushQN(p ^ e)
            for q, r in H:
                if r < li:
                    if l3+r < get(p & q, 17): L[p & q] = l3+r; QS[l3+r].append(p & q)
                    if l3+r < get(p ^ q, 17): L[p ^ q] = l3+r; QS[l3+r].append(p ^ q)
                elif r == li:
                    if p & q not in L: L[p & q] = 16
                    if p ^ q not in L: L[p ^ q] = 16
                else: break
            l < 7 and push((p, l))
        elif l1 < get(p ^ e, 17): L[p ^ e] = l1
print(*map(L.__getitem__, eval("e&"+",e&".join(open(0).read().replace(*"-~").replace(*"*&").replace(*"1e").split()[:-1]))),sep='\n')

Fixed submission:
def make(n):
    C = {0: 0}
    for i in range(n):
        b = int(input(), 2)
        for k, v in dict(C).items():
            if C.get(k^b, 0) < v+1:
                C[k^b] = v+1
    return C
def calc(P, Q):
    yield 0
    for k, v in P.items():
        if k in Q:
            yield v + Q[k]
def solve():
    while 1:
        n, m = map(int, input().split())
        if n+m == 0:
            break
        yield max(calc(make(n//2), make(n-n//2)))
print(*solve(), sep="\n")

Buggy python submission (verdict: Runtime Error):
a=65280; b=61680; c=52428; d=43690; e=65535
QS = [[] for i in range(17)]
QS[1] = [a, b, c, d]
L = {a: 1, b: 1, c: 1, d: 1, e: 1, e: 1, 0: 1}
H = []
get = L.get
push = H.append
for l in range(1, 16):
    Q = QS[l]
    li = 13-l; l3 = l+3; l1 = l+1
    pop = Q.pop
    pushQN = QS[l1].append
    while Q:
        p = pop()
        if L[p] < l: continue
        if l < 13:
            if l1 < get(p ^ e, 17):
                L[p ^ e] = l1
                pushQN(p ^ e)
            for q, r in H:
                if r < li:
                    if l3+r < get(p & q, 17): L[p & q] = l3+r; QS[l3+r].append(p & q)
                    if l3+r < get(p ^ q, 17): L[p ^ q] = l3+r; QS[l3+r].append(p ^ q)
                elif r == li:
                    if p & q not in L: L[p & q] = 16
                    if p ^ q not in L: L[p ^ q] = 16
                else: break
            l < 7 and push((p, l))
        elif l1 < get(p ^ e, 17): L[p ^ e] = l1
print(*map(L.__getitem__, eval("e&"+",e&".join(open(0).read().replace(*"-~").replace(*"*&").replace(*"1e").split()[:-1]))),sep='\n')

Fixed submission:
def make(n):
    C = {0: 0}
    for i in range(n):
        b = int(input(), 2)
        for k, v in dict(C).items():
            if C.get(k^b, 0) < v+1:
                C[k^b] = v+1
    return C
def calc(P, Q):
    yield 0
    for k, v in P.items():
        if k in Q:
            yield v + Q[k]
def solve():
    while 1:
        n, m = map(int, input().split())
        if n+m == 0:
            break
        yield max(calc(make(n//2), make(n-n//2)))
print(*solve(), sep="\n")