#include <bits/stdc++.h>
using namespace std;

int n;
char f[105];
int dig, up, lo, sp;

int main(){
	cin >> n;
	cin >> f;
	for ( int i = 0; i < n; i++ ){
		if ( isdigit(f[i]) ) dig++;
		else if ( isupper(f[i]) ) up++;
		else if ( islower(f[i]) ) lo++;
		else sp++;
	}
	
	int res = 0;
	if ( dig == 0 ){
		dig++;
		res++;
	}
	
	if ( up ==0 ){
		up++;
		res++;
	}
	
	if ( lo == 0 ){
		lo++;
		res++;
	}
	if ( sp == 0 ){
		sp++;
		res++;
	}
	
	while ( dig + sp + lo + up < 6 ){
		dig++;
		res++;
	}
	
	cout << res << endl;
	return 0;
}