题解 100% AC

#include<bits/stdc++.h>
using namespace std;
int n,k,a[1005],s,t,b[1005];
bool cmp(int x,int y){return x%3>y%3;}
int main(){
	cin>>n>>k;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		if(a[i]%3!=0)b[++t]=a[i];
	}
	sort(b+1,b+1+t,cmp);
	for(int i=k+1;i<=t;i++)s+=b[i]%3;
	cout<<s;
	return 0;
}