为啥0分啊

#include<bits/stdc++.h>
using namespace std;
int n,sum;
char opt,num;
int vis[100][20];
int main(){
	cin>>n;
	while(n--){
		cin>>opt>>num;
		int shu=0;
		if(num>='0'&&num<='9'){
			shu=num-'0';
		}
		else if(num=='A')shu=1;
		else if(num=='T')shu=10;
		else if(num=='J')shu=11;
		else if(num=='Q')shu=12;
		else if(num=='K')shu=13;
		
		if(opt=='D'){
			vis[shu][1]=1;
		}else if(opt=='C'){
			vis[shu][2]=1;
		}else if(opt=='H'){
			vis[shu][3]=1;
		}else if(opt=='S'){
			vis[shu][4]=1;
		}
		
	}
	for(int i=1;i<=100;i++){
		for(int j=1;j<=5;j++){
			if(vis[i][j])sum++;
		}
	}
	
	cout<<52-sum;
	return 0;
}