"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;
  });

  var b = input.filter(function (x, i, self) {
    return self.indexOf(x) === i;
  });

  console.log(b.length);
}

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