The term heterocyclic ring is identified in base64 scheme by the sequence aGV0ZXJvY3ljbGljIHJpbmc=, while the MD5 signature is equal to 7fd567fbf8c24863dcbc98584e90dbe4. The ASCII encoding of heterocyclic ring in hexadecimal notation is 68657465726f6379636c69632072696e67.