Pascal :

const dt=1000000;
type point=^node;
 node=record
   value:longint;
   link:point;
 end;
var n,m,i,j,ans,head,now,tail,pere,all:longint;
cost:array[1..dt] of longint;
color,vis:array[1..dt] of boolean;
a:array[1..dt+1000] of node;  //思考+1000的用意
deq:array[1..dt+1000] of longint;
s,q,p,t:point;
function min(a,b:longint):longint;
begin
  if a>b then exit(b) else exit(a);
end;
procedure add(x,y:longint);
begin
  if a[x].link=nil then
    begin
      new(p);
      a[x].link:=p;
      p^.value:=y;
      p^.link:=nil;
    end
else
        begin
          s:=a[x].link;
          while s <>nil do
            begin
              q:=s;
              s:=s^.link;
            end;
           new(p);
           p^.value:=y;
           p^.link:=nil;
           q^.link:=p;
        end;
end;
procedure init;
var i,x,y:longint;
begin
  all:=0;
  readln(n,m);
  for i:=1 to n do
    begin
      new(q);
      a[i].value:=i;
      a[i].link:=nil;
    end;
  for i:=1 to n do
    begin
    read(cost[i]);
    inc(all,cost[i]);
    end;
  for i:=1 to m do
    begin
      read(x,y);
      add(x,y);
      add(y,x);
    end;
end;
function bfs(state:boolean):boolean;
var i:longint; r:point;
begin
  fillchar(color,sizeof(color),false);
  fillchar(vis,sizeof(vis),false);
  bfs:=true;
  ans:=0;
  head:=1;
  tail:=1;
  deq[head]:=1;
  color[1]:=state;
  if state then inc(ans,cost[1]);
  vis[1]:=true;
    while head<=tail do
      begin
        now:=deq[head];
        r:=a[now].link;
        while r<>nil do
          begin
            if not vis[r^.value] then
              begin
                case color[now] of
                  true: color[r^.value]:=false;
                  false:
                    begin
                    color[r^.value]:=true;
                    inc(ans,cost[r^.value]);
                    end;
                end;
                inc(tail);
                deq[tail]:=r^.value;
                vis[r^.value]:=true;
              end
     else
 if not (color[now] xor color[r^.value]) then exit(false);
            r:=r^.link;
          end;
    inc(head);
    end;
end;
procedure print;
begin
  writeln('NO');
end;
begin
//assign(input,'Ezio.in');reset(input);
//assign(output,'Ezio.out');rewrite(output);
init;
 pere:=0;
 ans:=0;
if not bfs(true) then print
else writeln(min(ans,all-ans));
//close(input);close(output);
end.