
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		String s[] = new String[N];
		for (int i = 0; i < N; i++) {
			s[i] = sc.next();
		}
		String t[] = new String[N];
		for (int i = 0; i < N; i++) {
			char[] chars = s[i].toCharArray();
			Arrays.sort(chars);
			t[i] = new String(chars);
		}
		Arrays.sort(t);
		long ans = 0;
		int tmp = 0;
		for (int i = 0; i < N - 1; i++) {
			if (t[i].equals(t[i + 1])) {
				tmp++;
			} else {
				ans += ((long)(tmp+1)*tmp)/2; 
				tmp = 0;
			}
		}
			ans += ((long)(tmp+1)*tmp)/2; 
			tmp = 0;
		System.out.println(ans);
	}
}
/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