var obj = "A4NjFqYu5wPHsO0XTdDgMa2r1ZQocVte9UJBvk6/7=yRnhISGKblCWi+LpfE8xzm3";
var strs = '0c4a20131ebd12f0de2b54163fe318b1e'var r = "";
for (let i = 0;i < strs.length;) {
var ccc = '0c4a2013ebd12f0de2b54163fe318b1e'.charCodeAt(i++);
var iii = (ccc) >> 2;
var e = '0c4a2013ebd12f0de2b54163fe318b1e'.charCodeAt(i++);
var aaa =((3 & ccc) << 4) | (e >> 4);
var n = '0c4a2013ebd12f0de2b54163fe318b1e'.charCodeAt(i++);
var bbb =((15 & e) << 2) | (n >> 6);
var ccc = 63 & n;
isNaN(e)? (bbb = ccc = 64): isNaN(n) && (ccc = 64);
var r = r + obj.charAt(iii) + obj.charAt(aaa) + obj.charAt(bbb) + obj.charAt(ccc);
}
console.log(r)