# Codeblock 3
class FirstConv(nn.Module):
    def __init__(self):
        super().__init__()
        self.conv = nn.Conv2d(in_channels=3, 
                              out_channels=int(32*ALPHA),    #(1)
                              kernel_size=3,    #(2)
                              stride=2,         #(3)
                              padding=1,        #(4)
                              bias=False)       #(5)
        self.bn = nn.BatchNorm2d(num_features=int(32*ALPHA))
        self.relu = nn.ReLU()
    
    def forward(self, x):
        x = self.relu(self.bn(self.conv(x)))
        return x