import std.stdio, std.conv, std.string, std.array, std.range, std.algorithm, std.container;
import std.math, std.random, std.bigint, std.datetime, std.format;
void main(string[] args){ if(args.length > 1) if(args[1] == "-debug") DEBUG = 1; solve(); }
void log()(){ writeln(""); } void log(T, A ...)(T t, lazy A a){ if(DEBUG) write(t, " "), log(a); } bool DEBUG = 0; 
string read(){ static string[] ss; while(!ss.length) ss = readln.chomp.split; string res = ss[0]; ss.popFront; return res; }
// ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- //

void solve(){
	int n = read.to!int;
	
	char[][] ss;
	foreach(i; 0 .. n) ss ~= read.to!(char[]);
	
	long[char[10]] ucnt;
	foreach(s; ss){
		int[] v = s.map!(to!int).array;
		v.sort();
		char[10] u = v[0 .. 10].map!(to!char).array;
		if(u !in ucnt) ucnt[u] = 0;
		ucnt[u] += 1;
	}
	
	long ans;
	char[10][] uk = ucnt.keys;
	foreach(u; uk){
		long x = ucnt[u];
		ans += x * (x - 1) / 2;
	}
	
	ans.writeln;
}
