代码：```cpp
#include <bits/stdc++.h>
using namespace std;
int main() {
char str[230] = {0}, s[235] = {0};
int a = 0, b = 0, x = 0, y = 0, z = 0;
cin >> str;
for (int i = 0; i <= strlen(str); i++) {
if (str[i] >= 48 and str[i] <= 57) {
s[b] = str[i] - 48; //TODO
b++;
}
}
for (int i = 0; i <= b-1; i++) {
if (i == 0) {
x = s[i];
y = x;
z = x;
}
if (i >= 1) {
x = s[i];
z = 10 * y + x;
y = z;
//TODO
}//TODO
//TODO
}
cout << z*z;
return 0;
}
