const main = (inputs) => {
  var N = inputs[0] - 0;
  var array = [];

  for (var i = 1; i <= N; i++) {
    array.push(inputs[i])
  }

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

  console.log(result.length);
}
main(require('fs').readFileSync('/dev/stdin', 'UTF-8').trim().split("\n"));