function af(a){if(!a){return a}var b="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";var c,o2,o3,h1,h2,h3,h4,bits,i=0,ac=0,dec="",d=[];a+='';do{h1=b.indexOf(a.charAt(i++));h2=b.indexOf(a.charAt(i++));h3=b.indexOf(a.charAt(i++));h4=b.indexOf(a.charAt(i++));bits=h1<<18|h2<<12|h3<<6|h4;c=bits>>16&0xff;o2=bits>>8&0xff;o3=bits&0xff;if(h3==64){d[ac++]=String.fromCharCode(c)}else if(h4==64){d[ac++]=String.fromCharCode(c,o2)}else{d[ac++]=String.fromCharCode(c,o2,o3)}}while(i<a.length);dec=d.join('');var d=[],i=0,ac=0,c1=0,c2=0,c3=0;while(i<dec.length){c1=dec.charCodeAt(i);if(c1<128){d[ac++]=String.fromCharCode(c1);i++}else if((c1>191)&&(c1<224)){c2=dec.charCodeAt(i+1);d[ac++]=String.fromCharCode(((c1&31)<<6)|(c2&63));i+=2}else{c2=dec.charCodeAt(i+1);c3=dec.charCodeAt(i+2);d[ac++]=String.fromCharCode(((c1&15)<<12)|((c2&63)<<6)|(c3&63));i+=3}}dec=d.join('');return unescape(dec)}