Update app.py

app.py

@@ -201,7 +201,7 @@ def merge_lines(roman_file, w4w_file, full_mean_file, macaronic_file):
     with open(roman_file.name, "r") as f1, open(w4w_file.name, "r") as f2, \
             open(full_mean_file.name, "r") as f3, open(macaronic_file.name, "r") as f4:
         for lines in zip(f1, f2, f3, f4):
-            merged_line = "".join(line.strip() for line in lines)
+            merged_line = "\n".join(line.strip() for line in lines)
             merged_lines.append(merged_line)
 
     return "\n".join(merged_lines)