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"));

console.log(main());
function main(){
  var n = o.a();
  var x = o.a();
  var a = [1], b = [1];
  for(var i = 1; i <= n; i++){
    a[i] = a[i-1] * 2 + 3;
    b[i] = b[i-1] * 2 + 1;
  }
  return f(n,x);
  function f(n,x){
    if(a[n] === x)return b[n];
    if(x <= 0)return 0;
    if(n === 0)return 1;
    var m = (a[n]+1) / 2;
    if(x === m)return b[n-1] + 1;
    if(x < m)return f(n-1, x-1);
    return b[n-1] + 1 + f(n-1, x-m);
  }
}