为什么我暴力wa了2点？？？？

#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <cstring>
using namespace std;
int n,t,m,a[30],ans;
void dfs(int x,int num,int tleft,int book)//第x首歌放完，放了num张CD，第num张CD放了tleft分钟的歌，总共放了book首歌
{
    if (book+n-x<=ans) return;
    if (num==m || x==n) {ans=max(ans,book); return;}
    for (int i=x+1;i<=n;i++)
    {
        if (a[i]+tleft<=t) dfs(i,num,a[i]+tleft,book+1);
        if (a[i]<=t) dfs(i,num+1,a[i],book+1);
        dfs(i,num,tleft,book);
    }
}
int main()
{
    scanf("%d%d%d",&n,&t,&m);
    for (int i=1;i<=n;i++) scanf("%d",&a[i]);
    dfs(0,0,0,0);
    printf("%d",ans);
return 0;
}