#P16783. [蓝桥杯 2026 国 A] 密钥提取
[蓝桥杯 2026 国 A] 密钥提取
Problem Description
Xiao Lan is doing a security evaluation for an encryption algorithm based on big integer multiplication. During the evaluation, he uses this algorithm to generate two special keys and :
- Key consists of digits , that is, .
- Key consists of digits , that is, .
By computing their product, Xiao Lan gets an extremely long combined key .
To verify the integrity of this key during transmission, Xiao Lan needs to extract the digits at specific positions in the decimal representation of (counting from left to right, with no leading zeros). Let be the digits at the -th, -rd, and -nd positions of , respectively.
Now, please find the value of the three-digit integer formed by these three extracted digits in order. Here is the hundreds digit (it is guaranteed that ), is the tens digit, and is the ones digit. For example, if the three extracted digits are , then the answer you should submit is .
Output Format
This is an output-only (fill-in-the-blank) problem. You only need to compute the result and submit it. The result of this problem is an integer. When submitting, you only need to write a program that outputs this integer. Any extra content will result in no score.
Hint
Translated by ChatGPT 5