//start of jonathanirvings' template v3.0.3 (BETA)

#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
typedef pair<int,int> pii;
typedef pair<LL,LL> pll;
typedef pair<string,string> pss;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vii;
typedef vector<LL> vl;
typedef vector<vl> vvl;

double EPS = 1e-9;
int INF = 1000000005;
long long INFF = 1000000000000000005LL;
double PI = acos(-1);
int dirx[8] = {-1,0,0,1,-1,-1,1,1};
int diry[8] = {0,1,-1,0,-1,1,-1,1};

#ifdef TESTING
  #define DEBUG fprintf(stderr,"====TESTING====\n")
  #define VALUE(x) cerr << "The value of " << #x << " is " << x << endl
  #define debug(...) fprintf(stderr, __VA_ARGS__)
#else
  #define DEBUG 
  #define VALUE(x)
  #define debug(...)
#endif

#define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
#define FORN(a,b,c) for (int (a)=(b);(a)<=(c);++(a))
#define FORD(a,b,c) for (int (a)=(b);(a)>=(c);--(a))
#define FORSQ(a,b,c) for (int (a)=(b);(a)*(a)<=(c);++(a))
#define FORC(a,b,c) for (char (a)=(b);(a)<=(c);++(a))
#define FOREACH(a,b) for (auto &(a) : (b))
#define REP(i,n) FOR(i,0,n)
#define REPN(i,n) FORN(i,1,n)
#define MAX(a,b) a = max(a,b)
#define MIN(a,b) a = min(a,b)
#define SQR(x) ((LL)(x) * (x))
#define RESET(a,b) memset(a,b,sizeof(a))
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define ALL(v) v.begin(),v.end()
#define ALLA(arr,sz) arr,arr+sz
#define SIZE(v) (int)v.size()
#define SORT(v) sort(ALL(v))
#define REVERSE(v) reverse(ALL(v))
#define SORTA(arr,sz) sort(ALLA(arr,sz))
#define REVERSEA(arr,sz) reverse(ALLA(arr,sz))
#define PERMUTE next_permutation
#define TC(t) while(t--)

inline string IntToString(LL a){
  char x[100];
  sprintf(x,"%lld",a); string s = x;
  return s;
}

inline LL StringToInt(string a){
  char x[100]; LL res;
  strcpy(x,a.c_str()); sscanf(x,"%lld",&res);
  return res;
}

inline string GetString(void){
  char x[1000005];
  scanf("%s",x); string s = x;
  return s;
}

inline string uppercase(string s){
  int n = SIZE(s); 
  REP(i,n) if (s[i] >= 'a' && s[i] <= 'z') s[i] = s[i] - 'a' + 'A';
  return s;
}

inline string lowercase(string s){
  int n = SIZE(s); 
  REP(i,n) if (s[i] >= 'A' && s[i] <= 'Z') s[i] = s[i] - 'A' + 'a';
  return s;
}

inline void OPEN (string s) {
  #ifndef TESTING
  freopen ((s + ".in").c_str (), "r", stdin);
  freopen ((s + ".out").c_str (), "w", stdout);
  #endif
}

//end of jonathanirvings' template v3.0.3 (BETA)

struct BIT
{
  vi arr;
  void sz(int x) 
  {
    arr.resize(x+1);
    REP(i,x+1) arr[i] = 0;
  }
  void update(int x,int y)
  {
    int m = SIZE(arr);
    while (x < m)
    {
      MAX(arr[x],y);
      x += (x & -x);
    }
  }
  int query(int x)
  {
    int ret = 0;
    while (x > 0)
    {
      MAX(ret,arr[x]);
      x -= (x & -x);
    }
    return ret;
  }
};

BIT bit;
int xa,ya,xb,yb;
int n;
vector<pii> data;
int x,y;
vi angka;
map<int,int> ix;
int haha[200005];

int main()
{
  scanf("%d %d %d %d",&xa,&ya,&xb,&yb);
  double belok = PI * 5;
  double lurus = PI * 10;
  if (xa > xb) 
  {
    swap(xa,xb);
    swap(ya,yb);
  }
  scanf("%d",&n);
  TC(n)
  {
    scanf("%d %d",&x,&y);
    if (xa <= x && x <= xb && min(ya,yb) <= y && y <= max(ya,yb))
    {
      data.pb(mp(x,y));
      angka.pb(y);
    }
  }
  SORT(angka);
  REP(i,SIZE(angka))
  {
    if (ya <= yb) ix[angka[i]] = i + 1;
    else ix[angka[i]] = SIZE(angka) - i;
  }
  SORT(data);
  n = SIZE(data);
  REP(i,n) haha[i] = ix[data[i].se];
  bit.sz(n + 5);
  int risan = 0;
  REP(i,n)
  {
    int now = bit.query(haha[i]) + 1;
    bit.update(haha[i],now);
    MAX(risan,now);
  }
  double ashar = (xb - xa + abs(yb - ya)) * 100.0;
  ashar = ashar - risan * (20 - belok);
  if (min(xb - xa, abs(yb - ya)) + 1 == risan)
  {
    ashar += belok;
  }
  // VALUE(belok);
  printf("%.12lf\n",ashar);
  return 0;
}










Measured memory_bytes: 14064