1 #include<iostream>
  2 #include<cstdio>
  3 #include<cstring>
  4 #include<cmath>
  5 #include<algorithm>
  6 #define MAXN 100005
  7 using namespace std;
  8 int n,r=-1;
  9 
 10 inline void getnum(int &num)
 11 {
 12     num=0;
 13     int f=1;
 14     char c=getchar();
 15     while (!isdigit(c))
 16     {
 17         if (c==‘-‘)
 18             f=-1;
 19         c=getchar();
 20     }
 21     while (isdigit(c))
 22     {
 23         num=(num<<3)+(num<<1)+c-‘0‘;
 24         c=getchar();
 25     }
 26     num*=f;
 27     return;
 28 }
 29 
 30 struct Segment
 31 {
 32     int len,xl,xr,yu,yd;
 33     bool transe;
 34 }seg[MAXN];
 35 
 36 inline void add_seg(int num,int xa,int ya,int xb,int yb)
 37 {
 38     int l;
 39     if (xa==xb)
 40     {
 41         l=abs(ya-yb);
 42         seg[num].len=l;
 43         if (ya>yb)
 44             seg[num].yu=ya,seg[num].yd=yb;
 45         else
 46             seg[num].yu=yb,seg[num].yd=ya;
 47         seg[num].xr=seg[num].xl=xa;
 48         seg[num].transe=0;
 49     }
 50     else
 51     {
 52         l=abs(xa-xb);
 53         seg[num].len=l;
 54         if (xa>xb)
 55             seg[num].xr=xa,seg[num].xl=xb;
 56         else
 57             seg[num].xr=xb,seg[num].xl=xa;
 58         seg[num].yu=seg[num].yd=ya;
 59         seg[num].transe=1;
 60     }
 61     return;
 62 }
 63 
 64 inline bool cmp(Segment a,Segment b)
 65 {
 66     return a.len>b.len;
 67 }
 68 
 69 int main()
 70 {
 71     freopen("cross.in","r",stdin);
 72     freopen("cross.out","w",stdout);
 73     getnum(n);
 74     for (register int i=1;i<=n;i++)
 75     {
 76         int xa,ya,xb,yb;
 77         getnum(xa),getnum(ya),getnum(xb),getnum(yb);
 78         add_seg(i,xa,ya,xb,yb);
 79     }
 80     sort(seg+1,seg+1+n,cmp);
 81     for (register int i=1;i<=n;i++)
 82     {
 83         for (register int j=i+1;j<=n;j++)
 84         {
 85             if (seg[j].len/2<r)
 86                 break;
 87             if (seg[i].transe==seg[j].transe)
 88                 continue;
 89             if (seg[i].transe)
 90             {
 91                 if (seg[i].xr<=seg[j].xl||seg[i].xl>=seg[j].xr)
 92                     continue;
 93                 if (seg[j].yu<=seg[i].yd||seg[j].yd>=seg[i].yu)
 94                     continue;
 95                 int xmid=seg[j].xl,ymid=seg[i].yu;
 96                 r=max(r,min(min(xmid-seg[i].xl,seg[i].xr-xmid),min(seg[j].yu-ymid,ymid-seg[j].yd)));
 97             }
 98             else
 99             {
100                 if (seg[i].yu<=seg[j].yd||seg[i].yd>=seg[j].yu)
101                     continue;
102                 if (seg[j].xr<=seg[i].xl||seg[j].xl>=seg[i].xr)
103                     continue;
104                 int xmid=seg[i].xl,ymid=seg[j].yu;
105                 r=max(r,min(min(xmid-seg[j].xl,seg[j].xr-xmid),min(seg[i].yu-ymid,ymid-seg[i].yd)));
106             }
107         }
108     }
109     if (r<=0)
110         printf("Human intelligence is really terrible\n");
111     else
112         printf("%d\n",r);
113     return 0;
114 }