#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin>>n;
    string str;
    cin>>str;
    bool cond[6];
    int count=0,more=0,ans=0;
    char symbols[12]={'!','@','#','$','%','^','&','*','(',')','-','+'};
    memset(cond,false,sizeof(cond));
    if(n>=6)
        cond[1]=true;
    else more=6-n;
    for(int i=0;i<n;++i)
    {
        if(str[i]>='0' && str[i]<='9')
            cond[2]=true;
        else if(str[i]>='a' && str[i]<='z')
            cond[3]=true;
        else if(str[i]>='A' && str[i]<='Z')
            cond[4]=true;
        else 
        {
            for(int j=0;j<12;++j)
            {
                if(str[i]==symbols[j])
                {
                    cond[5]=true;
                    break;
                }
            }
        }
    }
    for(int i=2;i<=5;++i)
    {
        if(cond[i]==false)
            ++count;
    }
    if(count>=more)
        ans=count;
    else ans=more;
    cout<<ans;
    return 0;
}