#include <bits/stdc++.h>

using namespace std;


int main() {
    int n,answer=0;
    cin >> n;
    string s;
    cin >>s;
    int c[5]={0};
    if(n>=6)
        c[4]=1;
    for(int i=0;i<n;i++)
    {
        if(s[i]<58&&s[i]>=48)
            c[0]=1;
        if(s[i]<123&&s[i]>=97)
            c[1]=1;
        if(s[i]<91&&s[i]>=65)
            c[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]=='-')
            c[3]=1;
            
    }
    for(int i=0;i<4;i++)
        if(c[i]==0)
            answer++;
   if((n+answer)<6)
       answer+=6-n-answer;
    cout << answer << endl;
    return 0;
}