import java.util.*;
import java.util.Map.Entry;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner scan = new Scanner(System.in);
        Integer N = scan.nextInt();
        long count = 0;
        HashMap<String, Long> map = new HashMap<String, Long>(); 
        for(int i = 0; i < N; i++) {
            String s = scan.next();
            char[] sArray = s.toCharArray();
            Arrays.sort(sArray);
            String sorted = new String(sArray);
            if(map.containsKey(sorted))
                map.put(sorted, map.get(sorted) + 1);
            else
                map.put(sorted, (long)1);
        }
        for(Entry<String, Long> entry : map.entrySet()) {
            long value = entry.getValue();
            count += value * (value - 1) / 2;
        }
        System.out.println(count);
        
    }
}

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz