def calculateNetworkAddress(p):
    i = p.index('/')
    a = p[:i].split('.')
    n = int(p[i+1:])
    b = ('1'*n).zfill(32)[::-1]
    o = ''
    for i in 0,1,2,3:
        o += str(int(a[i])&int(b[:8],2))+'.'
        b=b[8:]
    return o[:-1]