#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;

#define each(i,a) for (auto&& i : a)
#define FOR(i,a,b) for (ll i=(a),__last_##i=(b);i<__last_##i;i++)
#define RFOR(i,a,b) for (ll i=(b)-1,__last_##i=(a);i>=__last_##i;i--)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define __GET_MACRO3(_1, _2, _3, NAME, ...) NAME
#define rep(...) __GET_MACRO3(__VA_ARGS__, FOR, REP)(__VA_ARGS__)
#define rrep(...) __GET_MACRO3(__VA_ARGS__, RFOR, RREP)(__VA_ARGS__)
#define pb push_back
#define all(a) (a).begin(),(a).end()
#define chmin(x,v) x = min(x, v)
#define chmax(x,v) x = max(x, v)

const ll linf = 1e18;
const int inf = 1e9;
const double eps = 1e-12;
const double pi = acos(-1);

template<typename T>
istream& operator>>(istream& is, vector<T>& vec) {
    each(x,vec) is >> x;
    return is;
}
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& vec) {
    rep(i,vec.size()) {
        if (i) os << " ";
        os << vec[i];
    }
    return os;
}
template<typename T>
ostream& operator<<(ostream& os, const vector< vector<T> >& vec) {
    rep(i,vec.size()) {
        if (i) os << endl;
        os << vec[i];
    }
    return os;
}
map<ll, ll> compress(vector<ll> v) {
    sort(all(v));
    v.erase(unique(all(v)), v.end());
    map<ll, ll> m;
    rep(i, v.size()) m[v[i]] = i;
    return m;
}
// SegmentTree<int> seg(n, 0x7FFFFFFF, [](int a, int b){return min(a, b);});
template <class T>
class SegmentTree {
    using func_t = function<T(T, T)>;
    const int sz, n;
    const T id;
    func_t merge;
    vector<T> data;
    int expand(int n) const { return n == 1 ? n : expand((n + 1) / 2) * 2; }
public:
    SegmentTree(const vector<T> &init, T id, func_t merge) :
        sz(init.size()), n(expand(sz)), id(id), data(n * 2, id), merge(merge) {
        copy(begin(init), end(init), begin(data)+n);
        RREP(i, n) {
            data[i] = merge(data[i * 2 + 0], data[i * 2 + 1]);
        }
    }
    int size() const { return sz; }
    void update(int p, T val) {
        assert (0 <= p && p < sz);
        data[p += n] = val;
        while (p /= 2) data[p] = merge(data[p * 2], data[p * 2 + 1]);
    }
    T find(int l, int r) const {
        assert (0 <= l && l <= r && r <= sz);
        l += n; r += n;
        T res1 = id, res2 = id;
        while (l != r) {
            if (l % 2) res1 = merge(res1, data[l++]);
            if (r % 2) res2 = merge(data[--r], res2);
            l /= 2; r /= 2;
        }
        return merge(res1, res2);
    }
};
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll sx, sy, gx, gy; cin >> sx >> sy >> gx >> gy;
    ll n; cin >> n;
    vector<P> v;
    rep(i, n) {
        ll x, y; cin >> x >> y;
        v.pb(P(x, y));
    }
    if (sx > gx) {
        swap(sx, gx);
        swap(sy, gy);
    }
    if (gy < sy) {
        gy *= -1;
        sy *= -1;
        each(p, v) p.second *= -1;
    }
    ll sx0 = sx, sy0 = sy, gx0 = gx, gy0 = gy;
    assert(sx <= gx && sy <= gy);
    cout << fixed << setprecision(10);
    auto f = [&](ll a, ll b) {
        double res = (gx0 - sx0) + (gy0 - sy0);
        res *= 100;
        res += (5 * pi - 20) * a;
        res += (10 * pi - 20) * b;
        // cout << a << " " << b << endl;
        return res;
    };
    auto check = [&]() {
        vector<P> v2 = v;
        sort(all(v2));
        rep(i, 1, v2.size()) {
            if (v2[i-1].second > v2[i].second) return;
        }
        ll t = ll(v2.size());
        if (gy - sy >= t && gx - sx >= t) return;
        assert(t >= 1);
        cout << f(t-1, 1) << endl;
        exit(0);
    };
    vector<P> nv;
    rep(i, n) {
        if (v[i].first < sx || v[i].first > gx) continue;
        if (v[i].second < sy || v[i].second > gy) continue;
        nv.pb(v[i]);
    }
    v = nv;
    n = v.size();
    check();
    vector<ll> X, Y;
    auto add = [&](P p) {
        X.pb(p.first);
        Y.pb(p.second);
    };
    add(P(sx, sy));
    add(P(gx, gy));
    each(p, v) add(p);
    map<ll, ll> mX = compress(X);
    map<ll, ll> mY = compress(Y);
    sx = mX[sx], sy = mY[sy];
    gx = mX[gx], gy = mY[gy];
    each(p, v) {
        p.first = mX[p.first];
        p.second = mY[p.second];
    }
    n = v.size();
    sort(all(v));
    ll yn = gy+1;
    SegmentTree<ll> seg(vector<ll>(yn, 0), 0, [](ll a, ll b) { return max(a, b); });
    rrep(i, v.size()) {
        P p = v[i];
        // cout << n << endl;
        // cout << p.second << " " << gy << endl;
        seg.update(p.second, seg.find(p.second, yn)+1);
    }
    cout << f(seg.find(0, yn), 0) << endl;
}


Measured memory_bytes: 42676