#include<bits/stdc++.h>


using namespace std ;

void solve(){
    int n, a = 0, b = 0, c = 0, d = 0, ans = 0  ;
    string s ;
    cin>>n ;
    getchar() ;
    cin>>s ;
    for(int i = 0; i < n; i++){
        if(s[i] >= 'a' && s[i] <= 'z') a++ ;
        if(s[i] >= 'A' && s[i] <= 'Z') b++ ;
        if(s[i] >= '0' && s[i] <= '9') c++ ;
        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] == '+' ) d++ ;

    }
    if(!a) ans += 1 ;
    if(!b) ans += 1 ;
    if(!c) ans += 1 ;
    if(!d) ans += 1 ;
    if((ans + n) < 6) cout<<ans + (6 -(ans+n))<<'\n' ;
    else cout<<ans<<'\n' ;
}

int main(){
	solve() ;
    return 0 ;
}