"use strict";

var main = function main(input) {
  var N = parseInt(input.split("\n")[0], 10);
  var d = input.split("\n").slice(1, input.split("\n").length - 1).filter(function (elem, idx, self) {
    return self.indexOf(elem) === idx;
  });
  console.log(d.length);
};

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