#include <cstdio>
#include <algorithm>
using namespace std;
char a[105];
bool number, lc, uc, sc;
int main() {
	int n, i, ans;
	scanf("%d", &n);
	scanf("%s", a);
	ans = 4;
	number = lc = uc = sc = 0;
	for(i = 0; i < n; i++) {
		if(number == 0 && (a[i] >= '0' && a[i] <= '9')) {
			number = 1; ans--;
		}
		if(lc == 0 && (a[i] >= 'a' && a[i] <= 'z')) {
			lc = 1; ans--;
		}
		if(uc == 0 && (a[i] >= 'A' && a[i] <= 'Z')) {
			uc = 1; ans--;
		}
		if(sc == 0 && (a[i] == '!' || a[i] == '@' || a[i] == '#' || a[i] == '$' || a[i] == '%' || a[i] == '^' || a[i] == '&' || a[i] == '*' || a[i] == '(' || a[i] == ')' || a[i] == '-' || a[i] == '+')) {
			sc = 1; ans--;
		}
	}
	if(n + ans >= 6) {
		printf("%d\n", ans);
	}
	else {
		printf("%d\n", 6 - n);
	}
	return 0;
}