# Codeblock 3
convblock = ConvBlock(in_channels=3,       #(1)
                      out_channels=64,     #(2)
                      kernel_size=7,       #(3)
                      stride=2,            #(4)
                      padding=3,           #(5)
                      maxpool_flag=True)   #(6)
x = torch.randn(1, 3, 448, 448)            #(7)
out = convblock(x)