#include<bits/stdc++.h>
using namespace std;
struct poker{
    int number,color;
}a[55];

int n,sum_a,flag;
string s;

int main(){
    cin>>n>>s;
    for(int i=1;i<=n;i+=2){
        switch(s[i-1]){
            case 'D':a[i].color = 0;break;
            case 'C':a[i].color = 1;break;
            case 'H':a[i].color = 2;break;
            case 'S':a[i].color = 3;break;
        }
        switch(s[i]){
            case 'A':a[i].number=1;break;
            case 'T':a[i].number=10;break;
            case 'J':a[i].number=11;break;
            case 'Q':a[i].number=12;break;
            case 'K':a[i].number=13;break;
            default:a[i].number=s[i]-'0';break;
        }
    }
    for(int i=1;i<=n;i++){
        flag=0;
        for(int j=i-1;j>=2;j--){
            if(a[i].number == a[j].number&&a[i].color == a[j].color){
                flag=1;
                break;
            }
        }
        if(!flag) sum_a++;
    }
    cout<<52-sum_a;
    return 0;
}