"use strict";
function Main(input) {
  input = input.split("\n");
  const num = input.shift();

  input.sort(function (a, b) {
    return parseInt(a) < parseInt(b) ? 1 : -1;
  });

  let arr = [];
  let n = 0;
  for (const i in input) {
    if (n === 0) {
      arr[n] = parseInt(input[i]);
      n++;
      continue;
    }
    if (arr[n - 1] > parseInt(input[i])) {
      arr[n] = parseInt(input[i]);
      n++;
    }
  }

  console.log(arr.length);
}

Main(require("fs").readFileSync("/dev/stdin", "utf-8"));
