//set many funcs template
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<stdbool.h>
#define inf 1072114514
#define llinf 4154118101919364364
#define mod 1000000007
#define pi 3.1415926535897932384

int max(int a,int b){if(a>b){return a;}return b;}
int min(int a,int b){if(a<b){return a;}return b;}
int zt(int a,int b){return max(a,b)-min(a,b);}
int round(int a,int b){if((a%b)*2 >= b){return (a/b)+1;}return a/b;}
int ceil(int a,int b){if(a%b==0){return a/b;}return (a/b)+1;}
int gcd(int a,int b){int c;while(b!=0){c=a%b;a=b;b=c;}return a;}
int lcm(int a,int b){int c=gcd(a,b);a/=c;return a*b;}
int nCr(int a,int b){int i,r=1;for(i=1;i<=b;i++){r*=(a+1-i);r/=i;}return r;}
int fact(int a){int i,r=1;for(i=1;i<=a;i++){r*=i;}return r;}
int pow(int a,int b){int i,r=1;for(i=1;i<=b;i++){r*=a;}return r;}
long long llmax(long long a,long long b){if(a>b){return a;}return b;}
long long llmin(long long a,long long b){if(a<b){return a;}return b;}
long long llzt(long long a,long long b){return llmax(a,b)-llmin(a,b);}
long long llround(long long a,long long b){if((a%b)*2 >= b){return (a/b)+1;}return a/b;}
long long llceil(long long a,long long b){if(a%b==0){return a/b;}return (a/b)+1;}
long long llgcd(long long a,long long b){long long c;while(b!=0){c=a%b;a=b;b=c;}return a;}
long long lllcm(long long a,long long b){long long c=llgcd(a,b);a/=c;return a*b;}
long long llnCr(long long a,long long b){long long i,r=1;for(i=1;i<=b;i++){r*=(a+1-i);r/=i;}return r;}
long long llfact(long long a){long long i,r=1;for(i=1;i<=a;i++){r*=i;}return r;}
long long llpow(long long a,long long b){long long i,r=1;for(i=1;i<=b;i++){r*=a;}return r;}
double dbmax(double a,double b){if(a>b){return a;}return b;}
double dbmin(double a,double b){if(a<b){return a;}return b;}
double dbzt(double a,double b){return dbmax(a,b)-dbmin(a,b);}
int sortfncsj(const void *a,const void *b){if(*(int *)a>*(int *)b){return 1;}if(*(int *)a==*(int *)b){return 0;}return -1;}
int sortfnckj(const void *a,const void *b){if(*(int *)a<*(int *)b){return 1;}if(*(int *)a==*(int *)b){return 0;}return -1;}
int llsortfncsj(const void *a,const void *b){if(*(long long *)a>*(long long *)b){return 1;}if(*(long long *)a==*(long long *)b){return 0;}return -1;}
int llsortfnckj(const void *a,const void *b){if(*(long long *)a<*(long long *)b){return 1;}if(*(long long *)a==*(long long *)b){return 0;}return -1;}
int dbsortfncsj(const void *a,const void *b){if(*(double *)a>*(double *)b){return 1;}if(*(double *)a==*(double *)b){return 0;}return -1;}
int dbsortfnckj(const void *a,const void *b){if(*(double *)a<*(double *)b){return 1;}if(*(double *)a==*(double *)b){return 0;}return -1;}
int strsortfncsj(const void *a,const void *b){return strcmp((char *)a,(char *)b);}
int strsortfnckj(const void *a,const void *b){return strcmp((char *)b,(char *)a);}

typedef struct{
    int par;
    int dep;
}node;

node uft[524288];

void resuf(){
    int i;
    for(i=0;i<524288;i++){
        uft[i].par=i;uft[i].dep=i;
    }
    return;
}

int find(int x){
    if(uft[x].par==x){return x;}
    else{uft[x].par=find(uft[x].par);return uft[x].par;}
}

void uni(int x,int y){
    int xp,yp;
    xp=find(x);yp=find(y);
    if(xp==yp){return;}
    if(uft[xp].dep>uft[yp].dep){
        uft[yp].par=xp;
    }
    else{
        uft[xp].par=yp;
        if(uft[xp].dep==uft[yp].dep){uft[yp].dep++;}
    }
    return;
}

typedef struct{
    long long st;
    long long fi;
    long long kr;
}rs;

typedef struct{
    long long st;
    long long kz;
}mkj;

int sortfnc(const void *a,const void *b){
if(((rs*)a)->st > ((rs*)b)->st){return 1;}
if(((rs*)a)->st < ((rs*)b)->st){return -1;}
if(((rs*)a)->fi > ((rs*)b)->fi){return 1;}
if(((rs*)a)->fi < ((rs*)b)->fi){return -1;}
return 0;
}

void makemkj(rs g[],mkj x[],long long n){
    long long i,ms=0,nst=g[0].st;
    for(i=1;i<n;i++){
        if(g[i].st!=g[i-1].st){
            x[nst].kz=i-ms;
            x[nst].st=ms;
            nst=g[i].st;ms=i;
        }
    }
    x[nst].kz=n-ms;
    x[nst].st=ms;
}

int main(void){
    resuf();
    long long fl[262144]={0},zs=0;
    long long ar[262144]={0},arp=0;
    long long nv,r=0;
    long long nc,i,j,n,m,k,a[262144],b,c,w,l,t,ux,uy;
    rs g[262144];
    mkj x[262144];
    double d;
    char s[262144];
    scanf("%lld%lld",&n,&m);
    //l=strlen(s);
    for(i=0;i<n;i++){scanf("%lld",&a[i]);}
    for(i=0;i<m;i++){scanf("%lld%lld",&ux,&uy);
        uni(ux,uy);
    }
    for(i=0;i<n;i++){
        g[i].st=find(i);
        fl[g[i].st]=1;
        g[i].fi=a[i];
    }
    for(i=0;i<n;i++){
        zs+=fl[i];
    }
    nv=(zs-1)*2;
    if(nv==0){printf("0\n");return 0;}
    qsort(g,n,sizeof(rs),sortfnc);
    makemkj(g,x,n);
    for(nc=0;nc<n;nc++){
    for(i=x[nc].st;i<x[nc].st+x[nc].kz;i++){
        if(i==x[nc].st){nv--;r+=g[i].fi;}
        else{ar[arp]=g[i].fi;arp++;}
    }
    }
    qsort(ar,arp,sizeof(long long),llsortfncsj);
    for(i=0;i<nv;i++){
        //printf("<%d>\n",ar[i]);
        if(i>=arp){printf("Impossible\n");return 0;}
        r+=ar[i];
    }
    printf("%lld\n",r);
    return 0;
}

Measured memory_bytes: 19232