#include<bits/stdc++.h>
using namespace std;
const int N = 305;
#define F(i,a,b) for(int i=a;i<=b;i++)
int n,ans;
char a,b;
string x = "DCHS",y = "A23456789TJQK";
bool vis[N][N];
int main()
{
    cin>>n;
    F(i,1,n)
    {
        cin>>a>>b;
        vis[a][b] = 1;
    }
    for(int i = 0;i<x.size();i++)
        for(int j = 0;j<y.size();j++)
            if(!vis[x[i]][y[j]]) ans++;
    cout << ans << '\n';
    return 0;
}