#include <iostream>#include <iomanip>#include <sstream>#include <string>#include <cstdio>#include <algorithm>#include <cstring>#include <cctype>#include <cmath>#include <vector>#include <queue>#include <stack>#include <map>#include <set>#include <bitset>#define ee 1e-10using namespace std;struct data{ int x,y; double dis;};double a[10][2];data d[10];double f[10][10];int tot;double calc(int i,int j){ double dx=a[i][0]-a[j][0],dy=a[i][1]-a[j][1]; return sqrt(dx*dx+dy*dy);}int dcmp(double x){ if (fabs(x)<ee) return 0;else return x<0?-1:1;}int main(){ while (cin>>a[0][0]>>a[0][1]) { for (int i=1;i<=3;i++) cin>>a[i][0]>>a[i][1]; tot=0; for (int i=0;i<4;i++) for (int j=i+1;j<4;j++) { f[i][j]=f[j][i]=calc(i,j); tot++; d[tot].x=i; d[tot].y=j; d[tot].dis=f[i][j]; } for (int i=1;i<6;i++) for (int j=i+1;j<=6;j++) if (dcmp(d[i].dis-d[j].dis)>0) swap(d[i],d[j]); if (d[1].x+d[1].y+d[2].x+d[2].y==6) { printf("%.7lfn",d[1].dis+d[2].dis); } else { int p1,p2,p3,p4; if (d[1].x==d[2].x) { p1=d[1].x; p2=d[1].y; p3=d[2].y; } if (d[1].x==d[2].y) { p1=d[1].x; p2=d[1].y; p3=d[2].x; } if (d[1].y==d[2].x) { p1=d[1].y; p2=d[1].x; p3=d[2].y; } if (d[1].y==d[2].y) { p1=d[1].y; p2=d[1].x; p3=d[2].x; } p4=6-p1-p2-p3; double tmp1=f[p2][p4]-f[p1][p2]; double tmp2=f[p3][p4]-f[p1][p3]; double tmp3=f[p1][p4]+f[p2][p3]-f[p1][p2]-f[p1][p3]; if (dcmp(tmp2-tmp1)<0) tmp1=tmp2; if (dcmp(tmp3-tmp1)<0) tmp1=tmp3; if (dcmp(f[p1][p4]-tmp1)<0) tmp1=f[p1][p4]; printf("%.7lfn",f[p1][p2]+f[p1][p3]+tmp1); } } return 0;}
