#include <iostream>
#include <cmath>
#include <vector>

#ifndef M_PI
#define M_PI (3.1415926535897954)
#endif

#define EPSILON (1e-12)
#define EQ(x,y) (fabs((x)-(y)) <  EPSILON)
#define NE(x,y) (fabs((x)-(y)) >= EPSILON)
#define LT(x,y) (((x)-(y)) <= -EPSILON)
#define LE(x,y) (((x)-(y)) <  +EPSILON)
#define GT(x,y) (((x)-(y)) >= +EPSILON)
#define GE(x,y) (((x)-(y)) >  -EPSILON)

using namespace std;

struct point_t
{
    double x, y;
};

bool operator <(const point_t &p1, const point_t &p2)
{
    if(EQ(p1.y, p2.y)) return p1.x < p2.x;
    return p1.y < p2.y;
}

double dist2(const point_t &p1, const point_t &p2)
{
    return (p1.x - p2.x) * (p1.x - p2.x) + (p1.y - p2.y) * (p1.y - p2.y);
}

int main(void)
{
    int N;
    double L;

    while(cin >> N >> L) {
        if(N == 0 && L == 0.0) break;

        vector<point_t> v(N);
        int k = 0;

        for(int i = 0; i < N; i++) {
            cin >> v[i].x >> v[i].y;
            if(v[i] < v[k]) k = i;
        }

        int s = k;
        double t = 0.0;
        double l = 0.0;

        while(true) {
            double pmin = 2.0 * M_PI;
            double dmax = 0.0;
            int kk = 0;

            for(int i = 0; i < N; i++) {
                if(i == k) continue;
                double p = atan2(v[i].y - v[k].y, v[i].x - v[k].x) - t;
                while(LT(p, 0.0)) p += 2.0 * M_PI;
                double d = dist2(v[i], v[k]);

                if(LT(p, pmin) || (EQ(p, pmin) && GT(d, dmax))) {
                    kk = i;
                    pmin = p;
                    dmax = d;
                }
            }

            l += sqrt(dmax);
            t += pmin;

            if(kk == s) break;
            k = kk;
        }

        cout << floor(l + 2 * M_PI * L + .5) << endl;
    }

    return 0;
}