import std.array;
import std.algorithm;
import std.range;
import std.stdio;

void main() {
  int n;
  readf!"%d\n"(n);
  int[] d;
  d.length = n;
  for (int i = 0; i < n; ++i) {
      readf!"%d\n"(d[i]);
  }
  writeln(d.sort.uniq.count!"true");
}
