#include<cstdio>

#include<cmath>

#include<algorithm>

using namespace std;

const int N=1005;

const double pi=acos(-1);

struct Point

{

    double x,y;

    Point(double x=0,double y=0):x(x),y(y){}

}p[N];

int T,n,L;

int q[N];

inline Point operator - (Point a,Point b)

{

    return Point(a.x-b.x,a.y-b.y);

}

inline double Cross(Point a,Point b)

{

    return a.x*b.y-a.y*b.x;

}

inline double sqr2(double x){return x*x;}

inline double lenght(Point a,Point b)

{

    return sqrt(sqr2(a.x-b.x)+sqr2(a.y-b.y));

}

inline bool cmp(const Point &a,const Point &b)

{

    if(a.x==b.x)return a.y<b.y;

    return a.x<b.x;

}

inline int convexHull()

{

    sort(p+1,p+n+1,cmp);

    int m=0;

    for(register int i=1;i<=n;i++)

    {

        while(m>=2&&Cross(p[q[m]]-p[q[m-1]],p[i]-p[q[m-1]])<=0)m--;

        q[++m]=i;

    }

    int k=m;

    for(register int i=n-1;i>=1;i--)

    {

        while(m>k&&Cross(p[q[m]]-p[q[m-1]],p[i]-p[q[m-1]])<=0)m--;

        q[++m]=i;

    }

    if(n>1)m--;

    return m;

}

int main()

{

    scanf("%d",&T);

    while(T--)

    {

        scanf("%d%d",&n,&L);

        for(register int i=1;i<=n;i++)scanf("%lf%lf",&p[i].x,&p[i].y);

        int m=convexHull();double ans=0;

        for(register int i=2;i<=m;i++)ans+=lenght(p[q[i]],p[q[i-1]]);

        ans+=lenght(p[q[m]],p[q[1]]);

        ans+=2*pi*L;

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

        if(T)printf("\n");

    }

    return 0;

}