"use strict"
const create = () => {
    const input = require("fs").readFileSync("/dev/stdin", "utf8").trim().split("\n");
    const res = {
        "list": input, "index": 0, "max": input.length,
        "hasNext": function() {return this.index < this.max},
        "next": function() { if (!this.hasNext()) {throw "ArrayIndexOutOfBoundsException";}else{return this.list[this.index++];}}
    };
    return res;
}
const o = create();
const next = () => o.next()
const nextInt = () => parseInt(o.next())
const nextStrArray = () => o.next().split(" ")
const nextIntArray = () => o.next().split(" ").map(el => parseInt(el))
const nextCharArray = () => o.next().split("")
const hasNext = () => o.hasNext()
const myout = (...x) => console.log(...x)
const Main = () => {
    const N = nextInt()
    let m = {}
    while(hasNext()){
        let tmp = next().split("").sort().join("")
        if(!m[tmp]) m[tmp] = 1
        else m[tmp]++
    }
    let ans = 0
    for(let key of Object.keys(m)){
        let tmp = m[key]
        if(tmp >1) ans += tmp*(tmp-1)/2
    }
    console.log(ans)
}
Main()
