#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int i,n,c=0;
    string s;
    cin>>n>>s;
    bool arr[4]={0};
    for(i=0;i<n;++i)
    {
        if(s[i]>='a' && s[i]<='z')
            arr[0]=1;
        if(s[i]>='A' && s[i]<='Z')
            arr[1]=1;
        if(s[i]>='0' && s[i]<='9')
            arr[2]=1;
        if(s[i]=='!' || s[i]=='@' || s[i]=='#' || s[i]=='$' || s[i]=='%' || s[i]=='^' || s[i]=='&' || s[i]=='*' || s[i]=='(' || s[i]==')' || s[i]=='-' || s[i]=='+')
            arr[3]=1;
    }
    for(i=0;i<4;++i)
        if(!arr[i])
            c++;
    if(c+n<6)
        cout<<6-n;
    else
        cout<<c;
    return 0;
}