'use strict'

function main(s) {

  const orders = s.split('\n').slice(1, -1).map(n => Number(n));
  const list = {};

  for (const num of orders) {
    if (list[num]) {
      delete list[num];
    } else {
      list[num] = num;
    }
  }

  const ans = Object.keys(list).length;
  console.log(ans);
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));
