Grammatical problems with nn.Sequential

Hi,
What is the syntax error here? How should I modify it?
微信图片_20200624141203

class Classifier(nn.Module):
    def __init__(self, input_nc):
        super(Classifier, self).__init__()
       
        self.classifier = nn.Sequential(
            # batch_size x input_nc x 256 x 256
            nn.Conv2d(input_nc, 32, kernel_size=5, stride=2, padding=2),
            nn.ReLU(True),
            # batch_size x 32 x 128 x 128
            nn.MaxPool2d(kernel_size=2, stride=2, padding=0)
            # batch_size x 32 x 64 x 64
            nn.Conv2d(32, 64, kernel_size=5, stride=2, padding=2),
            nn.ReLU(True),
            # batch_size x 64 x 32 x 32
            nn.MaxPool2d(kernel_size=2, stride=2, padding=0),
            # batch_size x 64 x 16 x 16
            nn.Conv2d(64, 128, kernel_size=5, stride=2, padding=2),
            nn.ReLU(True),
            # batch_size x 128 x 8 x 8
            nn.MaxPool2d(kernel_size=2, stride=2, padding=0),
            # batch_size x 128 x 4 x 4
            nn.Linear(2048, 512),
            nn.ReLU(True),
            # batch_size x 512
            nn.Linear(512, 128),
            nn.ReLU(True),
            # batch_size x 128
            nn.Linear(128, 3)
        )

missing a comma , after nn.MaxPool2d(kernel_size=2, stride=2, padding=0)

Thank! I neglected it.