#include <iostream>

int main()
{
	long int n, m;
	std::cin >> n >> m;
	if(n == 1)
		std::cout << m - 1;
	else if(m == 1)
		std::cout << n - 1;
	else
		std::cout << (n - 1) * (m - 1);
	std::cout << std::endl;
	return 0;
}