From a list of User-Agent strings, output Windows/Linux/Mac/Other counts in that fixed order.
Read User-Agent strings (one per line). For each, classify into ONE OS using these case-insensitive substring rules, checked in this order:
1. contains `windows` → Windows
2. contains `mac` → Mac
3. contains `linux` → Linux
4. otherwise → Other
Print exactly 4 lines:
```
Windows <count>
Linux <count>
Mac <count>
Other <count>
```
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