import torch
import torch.nn as nn

class SimpleCNN(nn.Module):
    def __init__(self):
        super().__init__()
        self.net = nn.Sequential(
            nn.Conv2d(3, 32, 3, padding=1), nn.ReLU(), nn.MaxPool2d(2),
            nn.Conv2d(32, 64, 3, padding=1), nn.ReLU(), nn.MaxPool2d(2),
            nn.Conv2d(64, 128, 3, padding=1), nn.ReLU(), nn.AdaptiveAvgPool2d(1),
        )
        self.fc = nn.Linear(128, 2)  # Negative=0, Positive=1

    def forward(self, x):
        x = self.net(x)
        x = x.view(x.size(0), -1)
        return self.fc(x)