#include <iostream>
#include <string>
#include <algorithm>
bool P(int value)
{
std::string left = std::to_string(value);
std::reverse(left.begin(), left.end());
std::string right = std::to_string(value);;
return left == right;
}
int main()
{
int n;
std::cin >> n;
int count = 0;
for (int i = 1; i <= n; ++i)
{
if (P(i))
{
count++;
}
}
std::cout << "Count palindrome: " << count << std::endl;
return 0;
}
#include <iostream>
#include <vector>
#include <cstdlib>
#include <ctime>
#include <algorithm>
using namespace std;
int main() {
float n;
cin >> n;
if (n <= 1) {
cout << "wrong data";
return 0;
}
float P = (1-1/2*2)*(1-1/3*3);
for (int i = 3; i <= n; ++i) {
P *= (1 - 1 / (n * n));
}
cout << P;
}