/* 1348 */

 #include <iostream>

 #include <cstdio>

 #include <cstring>

 #include <cstdlib>

 #include <cmath>

 #include <algorithm>

 using namespace std;

 #define MAXN 1005

 typedef struct Point_t {

     double x, y;

     Point_t() {}

     Point_t(double xx, double yy) {

         x = xx; y = yy;

     }

 } Point_t;

 Point_t stack[MAXN];

 Point_t points[MAXN];

 const double PI = acos(-1.0);

 int n;

 double Length(Point_t a, Point_t b) {

     return sqrt((a.x-b.x)*(a.x-b.x) + (a.y-b.y)*(a.y-b.y));

 }

 double cross(Point_t p0, Point_t p1, Point_t p2) {

     return (p1.x - p0.x) * (p2.y - p0.y) - (p2.x - p0.x) * (p1.y - p0.y);

 }

 bool comp(Point_t a, Point_t b) {

     double k = cross(points[], a, b);

     return !(k< || (k== && Length(points[], a)>Length(points[], b)));

 }

 double Graham() {

     double ret = ;

     int i, j, k;

     int top;

     Point_t p0;

     p0 = points[];

     k = ;

     for (i=; i<n; ++i) {

         if (points[i].x<p0.x || (points[i].x==p0.x && points[i].y<p0.y)) {

             p0 = points[i];

             k = i;

         }

     }

     points[k] = points[];

     points[] = p0;

     sort(points+, points+n, comp);

     stack[] = points[];

     stack[] = points[];

     stack[] = points[];

     top = ;

     for (i=; i<n; ++i) {

         while (cross(stack[top-], stack[top], points[i])<= && top>)

             --top;

         stack[++top] = points[i];

     }

     stack[++top] = p0;

     for (i=; i<=top; ++i)

         ret += Length(stack[i-], stack[i]);

     return ret;

 }

 int main() {

     int t;

     int i, j, k, tmp;

     double l, ans;

     #ifndef ONLINE_JUDGE

         freopen("data.in", "r", stdin);

     #endif

     scanf("%d", &t);

     while (t--) {

         scanf("%d %lf", &n, &l);

         for (i=; i<n; ++i)

             scanf("%lf %lf", &points[i].x, &points[i].y);

         ans = Graham();

         ans += PI * (l+l);

         printf("%.0lf\n", ans);

         if (t)

             printf("\n");

     }

     return ;

 }