P8690 [Lanqiao Cup 2019 National B] Fill-in-the-Blank Problems.
Description
## Task $\mathrm{A}$: Square Sequence.
### Problem Description.
Xiaoming wants to find two positive integers $X$ and $Y$ such that:
- $2019
Input Format
Input an uppercase letter indicating which task it is.
Output Format
According to the input task letter, output the answer for the corresponding task.
Explanation/Hint
Answer template, for reference.
```cpp
#include
using namespace std;
int main() {
string ans [] = {
"The answer of task A", // 双引号中替换为 A 题的答案
"The answer of task B", // 双引号中替换为 B 题的答案
"The answer of task C", // 双引号中替换为 C 题的答案
"The answer of task D", // 双引号中替换为 D 题的答案
"The answer of task E", // 双引号中替换为 E 题的答案
};
char T;
cin >> T;
cout