def minimumNumber(n, password):
    count = 0    
    if any(i.isdigit() for i in password)==False:
        count+=1
    if any(i.islower() for i in password)==False:
        count+=1
    if any(i.isupper() for i in password)==False:
        count+=1
    if any(i in '!@#$%^&*()-+' for i in password)==False:
        count+=1
    return max(count,6-n)

int CharFamily(char c) 
{
   if(c >= '0' && c <= '9') return 0;
   if(c >= 'a' && c <= 'z') return 1;
   if(c >= 'A' && c <= 'Z') return 2;
   return 3;
}

int main() 
{
    int n; cin >> n;
    char c;
    bitset<4> mask;

    while (cin >> c)
    {
        mask.set(CharFamily(c));
    }
    cout << max(6-n, 4-(int)mask.count());
}

private static int checkPass(String s) {
		int count = 0;
		
		Pattern patternDigit = Pattern.compile("(\\d)");
		Pattern patternUpper = Pattern.compile("([A-Z])");
		Pattern patternLower = Pattern.compile("([a-z])");
		Pattern patternSpecial = Pattern.compile("(\\W)");
        
		Matcher matcherDigit = patternDigit.matcher(s);
		Matcher matcherUpper = patternUpper.matcher(s);
		Matcher matcherLower = patternLower.matcher(s);
		Matcher matcherSpecial = patternSpecial.matcher(s);
		
		if (!matcherDigit.find()) {
			count++;
		}
		if (!matcherUpper.find()) {
			count++;
		}
		if (!matcherLower.find()) {
			count++;
		}
		if (!matcherSpecial.find()) {
			count++;
		}
		if ((count+s.length())<6) {
			count = count + 6-(count+s.length());
		}
		return count;
	}

static int minimumNumber(int n, String password) {
        
        int lc=0,uc=0,no=0,sc=0;
        int sum=0;
        
        String lowercase = ".*[a-z]+.*";
        String uppercase = ".*[A-Z]+.*";
        String num = ".*[0-9]+.*";
        String specialchar = ".*[-!@#$%^&*()+]+.*"; 
        //Regex for pattern matching
        
        if(!(password.matches(lowercase)))
            lc++; 
        //if there is no match to a lowercase,"lc" is increased by 1.
    
        if(!(password.matches(uppercase)))
            uc++; 
        //if there is no match to an uppercase,"uc" is increased by 1.
    
        if(!(password.matches(num)))
            no++; 
        //if there is no match to a number,"no" is increased by 1.
    
        if(!(password.matches(specialchar)))
            sc++; 
        //if there is no match to a specialCharacter,"sc" is increased by 1.
        
        
        sum=lc+uc+sc+no;
        
        return (sum>(6-n))?sum:(6-n);
    }