#include <iostream>#include <math.h>#include <cstdio>#define MAX 100000000using namespace std;double a[1001][1001],w[1001];bool b[1001];double x[1001],y[1001];int n;void Prim(){ int i,j,t; double tmp,len=0; for(i=1;i<=n;i++) { w[i]=a[1][i]; b[i]=false; } b[1]=true; for(i=2;i<=n;i++) { t=1; tmp=MAX; for(j=2;j<=n;j++) { if(!b[j]&&w[j]<tmp) { t=j; tmp=w[j]; } } len+=tmp; b[t]=true; for(j=2;j<=n;j++) { if(!b[j]&&w[j]>a[t][j]) w[j]=a[t][j]; } } printf("%.2fn",len);}int main(){ int m,i,j; scanf("%d%d",&n,&m); for(i=1;i<=n;i++) cin>>x[i]>>y[i]; for(i=1;i<=n;i++) for(j=1;j<=i;j++) { a[i][j]=sqrt((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j])); a[j][i]=a[i][j]; } while(m--) { scanf("%d%d",&i,&j); a[i][j]=0; a[j][i]=0; } Prim(); return 0;}
