1 #include <bits/stdc++.h>
2 #define _for(i,a,b) for(int i = (a);i < b;i ++)
3 #define _rep(i,a,b) for(int i = (a);i > b;i --)
4 #define INF 0x3f3f3f3f
5 #define PI 3.1415926535
6 typedef long long ll;
7 using namespace std;
8 inline ll read()
9 {
10 ll ans = 0;
11 char ch = getchar(), last = ' ';
12 while(!isdigit(ch)) last = ch, ch = getchar();
13 while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
14 if(last == '-') ans = -ans;
15 return ans;
16 }
17 inline void write(ll x)
18 {
19 if(x < 0) x = -x, putchar('-');
20 if(x >= 10) write(x / 10);
21 putchar(x % 10 + '0');
22 }
23 struct P
24 {
25 double x;
26 double y;
27 };
28 double height[2];
29 double width[2];
30 int vis[8];
31 P point[8];
32 double pointr[8];
33 int N;
34 double rnt = 0;
35 double reach(P p1,P p2)
36 {
37 return sqrt(pow(p1.x-p2.x,2)+pow(p1.y-p2.y,2));
38 }
39 double findr(int i)
40 {
41 double rnt = 10000;
42
43 rnt = min(rnt,min(point[i].x-width[0],width[1]-point[i].x));
44 rnt = min(rnt,min(point[i].y-height[0],height[1]-point[i].y));
45 _for(j,0,N)
46 {
47 if(i==j)
48 continue;
49 if(abs(reach(point[i],point[j])<pointr[j]))
50 rnt = 0;
51 if(pointr[j])
52 rnt = min(rnt,abs(reach(point[i],point[j])-pointr[j]));
53 }
54 return rnt;
55 }
56 void dfs(int step,double area)
57 {
58 if(step==N)
59 rnt = max(rnt,area);
60
61 _for(i,0,N)
62 {
63 if(!vis[i])
64 {
65 double r = findr(i);
66 pointr[i] = r;
67 vis[i] = 1;
68 dfs(step+1,area+PI*r*r);
69 vis[i] = 0;
70 pointr[i] = 0;
71 }
72 }
73 }
74 int main()
75 {
76 N = read();
77 width[0] = read(),height[0] = read(),width[1] = read(),height[1] = read();
78 sort(width,width+2);
79 sort(height,height+2);
80 _for(i,0,N)
81 point[i].x = read(),point[i].y = read();
82 memset(vis,0,sizeof(vis));
83 dfs(0,0);
84
85 write((width[1]-width[0])*(height[1]-height[0])-(int)(rnt+0.5));
86 return 0;
87 }
