def uint256_from_str(s):
    r = 0
    t = struct.unpack('<IIIIIIII', s[:32])
    for i in range(8):
        r += (t[i] << (i * 32))
    return r
def uint256_from_str(s):
    r = 0
    t = struct.unpack('<IIIIIIII', s[:32])
    for i in range(8):
        r += (t[i] << (i * 32))
    return r