import torch.nn as nn
from torchvision import models

# Custom ResNet model for monkey classification
class MonkeyResNet(nn.Module):
    def __init__(self, num_classes):
        super(MonkeyResNet, self).__init__()
        
        # Load pretrained ResNet18 model from torchvision
        self.model = models.resnet18(pretrained=False)
        
        # Replace the final fully connected layer to match number of classes
        in_features = self.model.fc.in_features
        self.model.fc = nn.Linear(in_features, num_classes)

    def forward(self, x):
        return self.model(x)  # run input through the model