#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string a) {
    int di=0,lo=0,upp=0,spp=0;
    for(int i=0;i<n;i++)
    {
        if(a[i]>=97&&a[i]<=122)
            lo=1;
        else if(a[i]>=65&&a[i]<=90)
            upp=1;
        else if(a[i]=='!'||a[i]=='@'||a[i]=='#'||a[i]=='$'||a[i]=='%'||a[i]=='^'||a[i]=='&'||a[i]=='*'||a[i]=='('||a[i]==')'||a[i]=='-'||a[i]=='+')
            spp=1;
        else if(a[i]-'0'>=0&&a[i]-'0'<=9)
            di=1;
    }
    //printf("%d %d %d %d\n",di,lo,upp,spp);
    int z=(!di)+(!lo)+(!upp)+(!spp);
    int ans=max(0,6-(z+n));
    ans+=z;
    return ans;
}

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