NOIP 2011 Day1 Problem1

#include<cstdio>
struct node
{
    int start_x;
    int start_y;
    int end_x;
    int end_y;
}a[10010];
int main()
{
    freopen("carpet.in","r",stdin);
    freopen("carpet.out","w",stdout);
    int n;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        int x,y;
        scanf("%d %d %d %d",&a[i].start_x,&a[i].start_y,&x,&y);
        a[i].end_x=a[i].start_x+x;
        a[i].end_y=a[i].start_y+y;
    }
    int x,y;
    scanf("%d %d",&x,&y);
    int now=-1;
    for(int i=1;i<=n;i++)
        if(x>=a[i].start_x && x<=a[i].end_x && y>=a[i].start_y && y<=a[i].end_y)
            now=i;
    printf("%d",now);
    return 0;
}