import java.util.*;

class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		sc.nextLine();
		HashMap<String,Integer> hm = new HashMap<>();
		for(int i = 0; i < n; i++){
		String s = sc.nextLine();
		char[] chr = s.toCharArray();
		Arrays.sort(chr);
		String str = String.valueOf(chr);
		hm.put(str, 1 + hm.getOrDefault(str,0));
		}
		long count = 0;
		for(long cur : hm.values()){
			count += (cur * (cur - 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