#include <iostream>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <limits.h>
#include <algorithm>
#include <math.h>

using namespace std;

int main()
{
	iostream::sync_with_stdio(0);
	cin.tie(0);

	int n, i, knowncnt = 0;
	cin >> n;

	for (i = 0; i < n; i++)
	{
		char l;
		cin >> l;
		if (l != '_') knowncnt++;
	}

	int ans = 1;
	for (i = 26-n+1; i <= 26-knowncnt; i++)
	{
		ans *= i;
	}
	cout << ans;
}