var GET=(function(){function f(s){return new g(s);}function g(s){this._s=s.trim().split("\n");this._y=0;}g.prototype.a=function(f){var s=this._s, y=this._y, r;if(typeof s[y]==="string")s[y]=s[y].split(" ").reverse();r=s[y].pop();if(!s[y].length)this._y++;return f?r:+r;};g.prototype.l=function(f){var s=this._s[this._y++].split(" ");return f?s:s.map(a=>+a);};g.prototype.m=function(n,f){var r=this._s.slice(this._y,this._y+=n).map(a=>a.split(" "));return f?r:r.map(a=>a.map(a=>+a));};g.prototype.r=function(n,f){var r=this._s.slice(this._y,this._y+=n);return f?r:r.map(a=>+a);};return f;})();
var o=GET(require("fs").readFileSync("/dev/stdin","utf8"));
function xArray(v){var a=arguments,l=a.length,r="Array(a["+--l+"]).fill(0).map(x=>{return "+v+";})";while(--l)r="Array(a["+l+"]).fill(0).map(x=>"+r+")";return eval(r);}

console.log(main());
function main(){
  var n = o.a();
  var x = xArray("new Set()",1e5);
  var y = xArray("new Set()",1e5);
  var a = o.m(n).sort((a,b)=>a[0]-b[0]);
  for(var i = 0; i < n; i++){
    a[i][0]--, a[i][1]--;
    x[a[i][1]].add(a[i][0]);
  }
  a.sort((a,b)=>a[1]-b[1]);
  for(var i = 0; i < n; i++){
    y[a[i][0]].add(a[i][1]);
  }
  for(var i = 0; i < 1e5; i++){
    if(x[i].size === 0)continue;
    if(x[i].size === 1){
      var t = Array.from(x[i])[0];
      if(y[t].size === 1){
        x[i].clear();
        y[t].clear();
      }
    }else{
      var f = 1;
      for(var j of x[i]){
        if(y[j].size > 1){
          f = 0;
          break;
        }
      }
      if(f){
        for(var j of x[i]){
          y[j].clear();
        }
        x[i].clear();
      }
    }
  }
  var h = 0, w = 0, p = 0;
  for(var i = 0; i < 1e5; i++){
    if(x[i].size){
      h++;
      p+=x[i].size;
    }
    if(y[i].size)w++;
  }
  return h*w-p;
}