#include <iostream>
#include <cstring>
using namespace std;
char C[101];
int gaseste(char C[],char S[])
{
    for(int i=0;i<strlen(C);i++)
        if(strchr(S,C[i]))
            return 1;
    return 0;
}
int main()
{
    int n;
    cin>>n;
    cin>>C;
    int len=strlen(C);
    if(!gaseste(C,"0123456789"))
        len++;
    if(!gaseste(C,"abcdefghijklmnopqrstuvwxyz"))
        len++;
    if(!gaseste(C,"ABCDEFGHIJKLMNOPQRSTUVWXYZ"))
        len++;
    if(!gaseste(C,"!@#$%^&*()-+"))
        len++;
    if(len<6)
        len=6;
    cout<<len-strlen(C);
    return 0;
}