#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
   int ar[4]={0},i;
    for(i=0;i<password.size();i++)
    {
        if(password[i]>='A'&&password[i]<='Z')
            ar[0]=1;
        else if(password[i]>='a'&&password[i]<='z')
            ar[1]=1;
        else if(password[i]>='0'&&password[i]<='9')
            ar[2]=1;
        else if(password[i]=='!'||password[i]=='@'||password[i]=='#'||password[i]=='$'||password[i]=='%'||password[i]=='^'||password[i]=='&'||password[i]=='*'||password[i]==50||password[i]==51||password[i]=='-'||password[i]=='+')
        {
            ar[3]=1;
        }
     }
    int sum=0;
    for(i=0;i<4;i++)
        sum+=ar[i];
    if(password.size()<6)
    {
        if((password.size()+(4-sum))>=6)
        {
            return 4-sum;
        }
        else
            return (6-((password.size())+(4-sum))+(4-sum));
    }
    else
        return 4-sum;
    
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
}