function Main(input){
  var inp= input.split("\n");
  var cnt = 0;
  var j;
  var text= [];
  var N = parseInt(inp[0]);

  var i;
  for(i=1;i<=N;i++){
    text.push(parseInt(inp[i]));

  }
 for (i = 0;i<N;i++){
   var flag = 1;
   for(j=i+1;j<=N;j++){
     if(text[i]==text[j]){flag=0;}
   }
     if(flag==1){cnt++;}  
 }
  console.log('%d',cnt);
}
  Main(require("fs").readFileSync("/dev/stdin","utf8"));
  