#include <iostream>
int main() {
int m;
int result = 1;
std::cout << "Enter a value of m: ";
std::cin >> m;
for (int i = 1; i <= m; i++) {
result *= 2*i;
}
std::cout << "The product of the first " << m << " even numbers is: " << result << std::endl;
return 0;
}