Update app.py

app.py

@@ -12,7 +12,7 @@ dataset = load_dataset("HuggingFaceH4/ultrachat_200k", split="train_sft")
 tokenizer = GPT2Tokenizer.from_pretrained("gpt2")
 
 class MyDataset(Dataset):
-    def __init__(self, data, max_length=1024):
+    def __init__(self, data, max_length=512):
         self.data = data
         self.max_length = max_length