#include <iostream>

using namespace std;

int main()
{
	int n, x = 0, abc = 26, i, out = 1;
	char temp;
	cin >> n;
	abc -= n;

	for (i = 0; i < n; i++)
	{
		cin >> temp;
		if (temp == '_')
		{
			x++, abc++;
		}
	}

	for (i = 0; i < x; i++)
	{
		out *= abc;
		abc--;
	}

	cout << out;
}