#include<stdio.h>
#include<utility>
#include<iostream>
#include<vector>
#include<queue>
using namespace std;
void scan(int &x)
{
    bool neg=false;
    register int c;
    x =0;
    c=getchar();
    if(c=='-')
    {
        neg = true;
        c=getchar();
    }
    for(;(c>47 && c<58);c=getchar())
        x = (x<<1) + (x<<3) +c -48;
    if(neg)
        x *=-1;
}
int main()
{
    int n,extra;
    string s;
    cin>>n>>s;
    int lower=0,upper=0,spe=0,digit=0;
    for(int i=0;i<n;i++)
    {
        if(s[i]>='a' && s[i]<='z')
            lower++;
        else if(s[i]>='A' && s[i]<='Z')
            upper++;
        else if(s[i]>='0' && s[i]<='9')
            digit++;
        else
            spe++;
    }
    if(spe==0)
        extra++;
    if(digit==0)
        extra++;
    if(lower==0)
        extra++;
    if(upper==0)
        extra++;
    if(s.length()+extra<6)
    {
        extra=6-s.length();
    }
    cout<<extra;
    return 0;
}