#include<bits/stdc++.h>
using namespace std;
int ans=52,m,n,k,l;
string s,c;
int main(){
cin>>m;
for(int i=1;i<=m;i++){
cin>>s;
if(s[0]=='D'){
k=1;
}else if(s[0]=='C'){
k=2;
}else if(s[0]=='H'){
k=3;
}else{
k=0;
}
if(c.find(char(s[1]-50+k*35))>0){
continue;
}else{
c[i]=char(s[1]-50+k*35);
ans--;
}
cout<<ans;
}
}
/**************************************************************
Problem: 2409
User: zhengzihao
Language: C++
Result: Wrong Answer
****************************************************************/