# Codeblock 4a
class Darknet(nn.Module):
    def __init__(self):
        super(Darknet, self).__init__()
        
        
        self.stage0 = nn.ModuleList([
            ConvBlock(3, 32, 3, 1),
            nn.MaxPool2d(kernel_size=2, stride=2)
        ])
        
        self.stage1 = nn.ModuleList([
            ConvBlock(32, 64, 3, 1),
            nn.MaxPool2d(kernel_size=2, stride=2)
        ])
            
        self.stage2 = nn.ModuleList([
            ConvBlock(64, 128, 3, 1), 
            ConvBlock(128, 64, 1, 0), 
            ConvBlock(64, 128, 3, 1),
            nn.MaxPool2d(kernel_size=2, stride=2)
        ])
        
        self.stage3 = nn.ModuleList([
            ConvBlock(128, 256, 3, 1), 
            ConvBlock(256, 128, 1, 0), 
            ConvBlock(128, 256, 3, 1),
            nn.MaxPool2d(kernel_size=2, stride=2)
        ])
        
        self.stage4 = nn.ModuleList([
            ConvBlock(256, 512, 3, 1), 
            ConvBlock(512, 256, 1, 0), 
            ConvBlock(256, 512, 3, 1), 
            ConvBlock(512, 256, 1, 0), 
            ConvBlock(256, 512, 3, 1), 
        ])
        
        self.stage5 = nn.ModuleList([
            nn.MaxPool2d(kernel_size=2, stride=2),    #(1)
            ConvBlock(512, 1024, 3, 1), 
            ConvBlock(1024, 512, 1, 0), 
            ConvBlock(512, 1024, 3, 1), 
            ConvBlock(1024, 512, 1, 0), 
            ConvBlock(512, 1024, 3, 1), 
        ])