This is the verification code of the calculation formula. The result of the calculation formula is the verification code to be entered.

The calculation result of the Bank of China verification code "1 4=?" in the question is 5, so enter 5

Extended information:

The verification code can prevent malicious intent Registration

Almost all formal forums require you to enter a verification code when registering. This is to prevent people who spam advertisements from using registration machines to register maliciously. This invention originated from Carnegie Mellon University in the United States is called CAPTCHA (fully automated Turing test for distinguishing humans and computers), because registrants need to identify the messy text on the picture, and this task Only a true human can accomplish it. There are hundreds of millions of Internet users around the world. For an individual, the few seconds it takes to identify text are insignificant, but if the power of all Internet users is harnessed, unimaginable and huge projects can be completed, and this is what the United States That's what a CMU research group in Pittsburgh, Pennsylvania, is doing.

The team was commissioned by a non-profit organization called the Internet Archive to convert a large number of ancient books and manuscripts into electronic texts through OCR (optical character recognition) software to facilitate computer storage and Query. However, due to the poor quality of the original manuscript, the poor computer would misread one word for every ten words it scanned. The only solution was manual verification, and such work was obviously not capable of being done by one person or a group. Therefore, CMU designed a powerful system called reCAPTCHA to allow their computers to ask humans for help. The specific method is to send scanned images of text that cannot be recognized by OCR software to major websites around the world to replace the original verification code images; after users of those websites correctly identify these words, their answers will be sent back to CMU.

In order to improve the accuracy of users in identifying text, they are often asked to identify two words, one of which has an answer already known. In this way, a user who correctly identifies the word with the answer is likely to also correctly identify the other word. Sometimes, CMU will also submit an unrecognized word to different users. If they get the same answer, then the answer is definitely correct.

Because many popular websites, such as Facebook, Twitter, and StumbleUpon, use reCAPTCHA, CMU can process approximately one million words per day. However, at the current rate, it is estimated that it will take 400 years to digitize all the texts provided by the Internet Archive.

Reference materials:

Verification code_Baidu Encyclopedia