def conv_bn(inp, oup, stride, k_size=3):
    return nn.Sequential(nn.Conv2d(inp, oup, k_size, stride, 1, bias=False), nn.BatchNorm2d(oup), nn.PReLU())
def conv_bn(inp, oup, stride, k_size=3):
    return nn.Sequential(nn.Conv2d(inp, oup, k_size, stride, 1, bias=False), nn.BatchNorm2d(oup), nn.PReLU())