蒟蒻初学，样例都没过

#include<bits/stdc++.h>
using namespace std;
int main(){
	int a[21][21][21]={1,},w,x,h,q;
	cin>>w>>x>>h>>q;
	int v=w*x*h,x1[q+1],x2[q+1],y1[q+1],y2[q+1],z1[q+1],z2[q+1];
	for(int i=1;i<=q;++i){
		cin>>x1[i]>>y1[i]>>z1[i]>>x2[i]>>y2[i]>>z2[i];
	}
	for(int i=1;i<=q;++i){
		for(int ii=1;ii<=w;++ii){
			for(int iii=1;iii<=x;++iii){
				for(int iiii=1;iiii<=h;++iiii){
					if(a[ii][iii][iiii]==1&&x1[i]<=ii&&x2[i]>=ii&&y1[i]<=iii&&iii<=y2[i]&&z1[i]<=iiii&&iiii<=z2[i]){
						a[ii][iii][iiii]=0;
						--v;
					}
				}
			}
		}
	}
	cout<<v;
	return 0;
}