#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <map>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <cstdio>
#include <cstring>
#include <iterator>
#include <bitset>
#include <unordered_set>
#include <unordered_map>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <utility>
#include <memory>
#include <functional>
#include <deque>
#include <cctype>
#include <ctime>
#include <numeric>
#include <list>
#include <iomanip>

#if __cplusplus >= 201103L
#include <array>
#include <tuple>
#include <initializer_list>
#include <forward_list>

#define cauto const auto&
#else

#endif

using namespace std;


typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef vector<int> vint;
typedef vector<vector<int> > vvint;
typedef vector<long long> vll;
typedef vector<vector<long long> > vvll;

#define VV(T) vector<vector< T > >

template <class T>
void initvv(vector<vector<T> > &v, int a, int b, const T &t = T()){
    v.assign(a, vector<T>(b, t));
}

template <class F, class T>
void convert(const F &f, T &t){
    stringstream ss;
    ss << f;
    ss >> t;
}

#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define _rep(i,n) _rep2((i),0,(n))
#define _rep2(i,a,b) for(int i=(a);i<(b);++i)
#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)
#define ALL(v) (v).begin(),(v).end()
#define PB push_back
#define fi first
#define se second
#define mkp make_pair
#define DEBUG
#ifdef DEBUG
#define dump(x)  cout << #x << " = " << (x) << endl;
#define debug(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#else
#define dump(x) 
#define debug(x) 
#endif

#define MOD 1000000007LL
#define EPS 1e-8
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
#define maxs(x,y) x=max(x,y)
#define mins(x,y) x=min(x,y)

int n;
double PI = acos(-1);

void ch(ll &x){
	ll geta = 1e8+10;
	x = -x + geta;
}

bool in(int a, int b, int c){
	return a<=c&&c<=b;
}

void mainmain(){
	ll x1,x2,y1,y2;
	cin>>x1>>y1>>x2>>y2;
	ll _x1 = x1;
	ll _x2 = x2;
	ll _y1 = y1;
	ll _y2 = y2;
	cin>>n;
	vector<pll> v(n);
	rep(i,n) cin>>v[i].fi>>v[i].se;

	double ans = 100.0 * (abs(x2-x1) + abs(y2-y1));
	if(x1>x2){
		swap(x1, x2);
		swap(y1, y2);
	}
	if(y1>y2){
		ch(y1);
		ch(y2);
		rep(i,n){
			ch(v[i].se);
		}
	}
	vint xx,yy;
	map<int,int> rankx;
	map<int,int> ranky;
	rep(i,n){
		xx.PB(v[i].fi);
		yy.PB(v[i].se);
	}
	xx.PB(x1);
	xx.PB(x2);
	yy.PB(y1);
	yy.PB(y2);
	sort(ALL(xx));
	xx.erase(unique(ALL(xx)), xx.end());
	sort(ALL(yy));
	yy.erase(unique(ALL(yy)), yy.end());
	rep(i,xx.size()){
		rankx[xx[i]] = rankx.size();
	}
	rep(i,yy.size()){
		ranky[yy[i]] = ranky.size();
	}
	rep(i,n){
		v[i].fi = rankx[v[i].fi];
		v[i].se = ranky[v[i].se];
	}
	x1 = rankx[x1];
	x2 = rankx[x2];
	y1 = ranky[y1];
	y2 = ranky[y2];
	sort(ALL(v));
	vll lis(n+10,INF);
	// lis[0] = -1;
	rep(i,n){
		if(!in(x1,x2,v[i].fi)) continue;
		if(!in(y1,y2,v[i].se)) continue;
		*lower_bound(ALL(lis), v[i].se) = v[i].se;
	}
	int tmp = lower_bound(ALL(lis), INF)-lis.begin();
	// tmp--;
	if(tmp == abs(_x2-_x1)+1 || tmp == abs(_y2-_y1)+1){
		tmp--;
		ans += -20 + PI*10;
	}
	ans += tmp*(-20+PI*5);
	cout<<ans<<endl;
}


signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout<<fixed<<setprecision(20);
    mainmain();
}

Measured memory_bytes: 25324