import core.bitop;
import std.algorithm;
import std.ascii;
import std.bigint;
import std.conv;
import std.functional;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.random;
import std.typecons;
import std.container;

alias sread = () => readln.chomp();
ulong bignum = 1_000_000_007;
alias SugarWater = Tuple!(long, "swater", long, "sugar");

T lread(T = long)()
{
    return readln.chomp.to!T();
}

T[] aryread(T = long)()
{
    return readln.split.to!(T[])();
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}

void main()
{
    auto n = lread();
    long[string] dict;
    foreach (_; iota(n))
    {
        auto s = sread();
        auto tmp = (cast(ubyte[]) s);
        tmp.sort();
        s = cast(string) tmp;
        if (s in dict)
            dict[s]++;
        else
            dict[s] = 1;
    }
    long ans;
    foreach (e; dict)
        if (e > 1)
            ans += e * (e - 1) / 2;
            
    ans.writeln();
}