Buggy python submission (verdict: Time Limit Exceeded):
def match(ch1, ch2):
    return ch1 == ch2 or ch1 == '?' or ch2 == '?'

def solve():
    MAXLEN = 2000
    a = raw_input()
    b = raw_input()
    c = raw_input()
    lA = len(a); lB = len(b); lC = len(c)
    MAXLEN = max(lA, lB, lC)
    ab = [True for i in range(10*MAXLEN)]
    ac = [True for i in range(10*MAXLEN)]
    bc = [True for i in range(10*MAXLEN)]
    for i in range(lA):
        for j in range(lB):
            if not match(a[i], b[j]):
                ab[i - j + 5 * MAXLEN] = False
    for i in range(lA):
        for j in range(lC):
            if not match(a[i], c[j]):
                ac[i - j + 5 * MAXLEN] = False
    for i in range(lB):
        for j in range(lC):
            if not match(b[i], c[j]):
                bc[i - j + 5 * MAXLEN] = False
    ret = lA + lB + lC
    for i in range(-2*MAXLEN, 2*MAXLEN+1):
        for j in range(-2*MAXLEN, 2*MAXLEN+1):
            if ab[i + 5*MAXLEN] and ac[j + 5*MAXLEN] and bc[j - i + 5*MAXLEN]:
                L = min(0, i, j)
                R = max(lA, lB + i, lC + j)
                ret = min(ret, R - L)
    print ret

if __name__ == '__main__':
    solve()


Fixed submission:
def match(ch1, ch2):
    return ch1 == ch2 or ch1 == '?' or ch2 == '?'

def solve():
    MAXLEN = 2000
    a = raw_input()
    b = raw_input()
    c = raw_input()
    lA = len(a); lB = len(b); lC = len(c)
    MAXLEN = max(lA, lB, lC)
    ab = [True for i in range(10*MAXLEN)]
    ac = [True for i in range(10*MAXLEN)]
    bc = [True for i in range(10*MAXLEN)]
    for i in range(lA):
        for j in range(lB):
            if not match(a[i], b[j]):
                ab[i - j + 5 * MAXLEN] = False
    for i in range(lA):
        for j in range(lC):
            if not match(a[i], c[j]):
                ac[i - j + 5 * MAXLEN] = False
    for i in range(lB):
        for j in range(lC):
            if not match(b[i], c[j]):
                bc[i - j + 5 * MAXLEN] = False
    ret = lA + lB + lC
    for i in range(-2*MAXLEN, 2*MAXLEN+1):
        for j in range(-2*MAXLEN, 2*MAXLEN+1):
            if i < -MAXLEN and j > 0:
                continue
            if i > MAXLEN and j < 0:
                continue
            if j < -MAXLEN and i > 0:
                continue
            if j > MAXLEN and i < 0:
                continue
            if ab[i + 5*MAXLEN] and ac[j + 5*MAXLEN] and bc[j - i + 5*MAXLEN]:
                L = min(0, i, j)
                R = max(lA, lB + i, lC + j)
                ret = min(ret, R - L)
    print ret

if __name__ == '__main__':
    solve()

Buggy python submission (verdict: Time Limit Exceeded):
MAXLEN = 2000

def match(ch1, ch2):
    return ch1 == ch2 or ch1 == '?' or ch2 == '?'

def solve():
    a = raw_input()
    b = raw_input()
    c = raw_input()
    lA = len(a); lB = len(b); lC = len(c)
    ab = [True for i in range(10*MAXLEN)]
    ac = [True for i in range(10*MAXLEN)]
    bc = [True for i in range(10*MAXLEN)]
    for i in range(lA):
        for j in range(lB):
            if not match(a[i], b[j]):
                ab[i - j + 5 * MAXLEN] = False
    for i in range(lA):
        for j in range(lC):
            if not match(a[i], c[j]):
                ac[i - j + 5 * MAXLEN] = False
    for i in range(lB):
        for j in range(lC):
            if not match(b[i], c[j]):
                bc[i - j + 5 * MAXLEN] = False
    ret = lA + lB + lC
    for i in range(-2*MAXLEN, 2*MAXLEN+1):
        for j in range(-2*MAXLEN, 2*MAXLEN+1):
            if ab[i + 5*MAXLEN] and ac[j + 5*MAXLEN] and bc[j - i + 5*MAXLEN]:
                L = min(0, i, j)
                R = max(lA, lB + i, lC + j)
                ret = min(ret, R - L)
    print ret

if __name__ == '__main__':
    solve()


Fixed submission:
def match(ch1, ch2):
    return ch1 == ch2 or ch1 == '?' or ch2 == '?'

def solve():
    MAXLEN = 2000
    a = raw_input()
    b = raw_input()
    c = raw_input()
    lA = len(a); lB = len(b); lC = len(c)
    MAXLEN = max(lA, lB, lC)
    ab = [True for i in range(10*MAXLEN)]
    ac = [True for i in range(10*MAXLEN)]
    bc = [True for i in range(10*MAXLEN)]
    for i in range(lA):
        for j in range(lB):
            if not match(a[i], b[j]):
                ab[i - j + 5 * MAXLEN] = False
    for i in range(lA):
        for j in range(lC):
            if not match(a[i], c[j]):
                ac[i - j + 5 * MAXLEN] = False
    for i in range(lB):
        for j in range(lC):
            if not match(b[i], c[j]):
                bc[i - j + 5 * MAXLEN] = False
    ret = lA + lB + lC
    for i in range(-2*MAXLEN, 2*MAXLEN+1):
        for j in range(-2*MAXLEN, 2*MAXLEN+1):
            if i < -MAXLEN and j > 0:
                continue
            if i > MAXLEN and j < 0:
                continue
            if j < -MAXLEN and i > 0:
                continue
            if j > MAXLEN and i < 0:
                continue
            if ab[i + 5*MAXLEN] and ac[j + 5*MAXLEN] and bc[j - i + 5*MAXLEN]:
                L = min(0, i, j)
                R = max(lA, lB + i, lC + j)
                ret = min(ret, R - L)
    print ret

if __name__ == '__main__':
    solve()