# Codeblock 11b
    def forward(self, x, t):  #(1)
        print(f'original\t\t: {x.size()}')
        print(f'timesteps\t\t: {t.size()}, {t}')
            
        convolved_0, maxpooled_0 = self.downsample_0(x, t)
        print(f'\nmaxpooled_0\t\t: {maxpooled_0.size()}')
            
        convolved_1, maxpooled_1 = self.downsample_1(maxpooled_0, t)
        print(f'maxpooled_1\t\t: {maxpooled_1.size()}')
            
        x = self.bottleneck(maxpooled_1, t)
        print(f'after bottleneck\t: {x.size()}')
    
        upsampled_0 = self.upsample_0(x, t, convolved_1)
        print(f'upsampled_0\t\t: {upsampled_0.size()}')
            
        upsampled_1 = self.upsample_1(upsampled_0, t, convolved_0)
        print(f'upsampled_1\t\t: {upsampled_1.size()}')
            
        x = self.output(upsampled_1)
        print(f'final output\t\t: {x.size()}')
            
        return x