#include <iostream>
#include <algorithm>
#include <stack>
#include <vector>
using namespace std;

int main(int argc, const char * argv[])
{
    int n;
    cin>>n;
    string s;
    cin>>s;
    int lc = 0, uc = 0, num = 0, sp = 0;
    for(int i = 0; i < n; i++)
    {
        if(isupper(s[i]))
        {
            uc++;
        }
        else if(islower(s[i]))
            lc++;
        else if(isdigit(s[i]))
            num++;
        else
            sp++;
    }
    int count = 0;
    if(lc == 0)
        count++;
    if(uc == 0)
        count++;
    if(num == 0)
        count++;
    if(sp == 0)
        count++;
    if(n + count < 6)
    {
        count += 6 - (n + count);
    }
    cout<<count<<endl;
}