How to delete more than one sequential layer in a model

vision
1

I write one class for my model. I want to use into another model, and want to delete three last sequential of that.

class SpermModel(nn.Module):
    def __init__(self):
        super(SpermModel, self).__init__()
        self.cnn_layers = model
        self.modi = torch.nn.Sequential(*(list(self.cnn_layers.children())[:-1]))
        self.fc = nn.Sequential(
            nn.Flatten(),
            nn.Linear(25088, 1024),
            nn.ReLU(),
            nn.Linear(1024, 2)
        )
        self.fc1 = nn.Sequential(
            nn.Flatten(),
            nn.Linear(25088, 1024),
            nn.ReLU(),
            nn.Dropout(0.2),
            nn.Linear(1024, 2)
        )
        self.fc2 = nn.Sequential(
            nn.Flatten(),
            nn.Linear(25088, 1024),
            nn.ReLU(),
            nn.Linear(1024, 2)
        )
    def forward(self, item):
        out = self.modi(item)
        out1 = self.fc(out)
        out2 = self.fc1(out)
        out3 = self.fc2(out)
        return out1, out2, out3

I used self.modi = torch.nn.Sequential(*(list(self.cnn_layers.children())[:-1])) for that, but it just delete one sequential layer.