#include<bits/stdc++.h>

#define X first
#define Y second
#define eb push_back
#define siz(a) int(a.size())
#define endl "\n"

#define trace2(x, y)             cout <<#x<<": "<<x<<" | "<<#y<<": "<<y<< endl;
#define trace3(x, y, z)          cout <<#x<<": "<<x<<" | "<<#y<<": "<<y<<" | "<<#z<<": "<<z<<endl;
#define trace4(a, b, c, d)       cout <<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<endl;
#define trace5(a, b, c, d, e)    cout <<#a<<": "<<a<<" | "<<#b<<": "<<b<<" | "<<#c<<": "<<c<<" | "<<#d<<": "<<d<<" | "<<#e<<": "<<e<<endl;

using namespace std;

typedef long long int ll;
typedef vector < int > vi;
typedef vector < ll > vll;

const int mod=1e9+7;
const int maxn=1e6+5;

/*	finding inverse upto n
 * for i in xrange(2, N):
    ifc[i] = -(mod / i) * ifc[mod % i] % mod
 * 
*/
ll power(ll base, ll exp){ll res = 1; while(exp){if(exp%2)res*=base;base*=base;res%=mod;base%=mod;exp/=2;}return res;}

//Work Harder :)
//Think More :(

int flag[5];

int main(){
	ios_base::sync_with_stdio(false);cin.tie(NULL); cout.tie(NULL);
	//freopen("input.in", "r", stdin);freopen("output.out", "w", stdout);	
	int n, i;
	cin >> n;
	
	string str;
	
	cin >> str;
	
	int ans = 0;
	
	for(i=0; i<siz(str); i++){
		
		if(str[i] >= 'a' && str[i] <= 'z')
			flag[0] = 1;
		
		else if(str[i] >= 'A' && str[i] <= 'Z')
			flag[1] = 1;
		
		else if(str[i] >= '0' && str[i] <= '9')
			flag[2] = 1;
		
		else
			flag[3] = 1;
		 
	}
	
	for(i=0; i<4; i++){
		if(!flag[i])
			ans++;
	}
	
	if(ans + n < 6)
		ans += 6 - (n + ans);
	
	cout << ans;
	
	return 0;
}