program prison;
const
 maxn=20000; maxm=100000;
var
  n,m:longint;
  f,s:array[0..maxn+1] of longint;
  a,b,c:array[0..maxm+1] of longint;
function findsets(k:longint):longint;
var
  y:longint;
begin
 if f[k]<>k then
  begin
   y:=f[k]; f[k]:=findsets(y);
   s[k]:=(s[k]+s[y]) mod 2;
  end;
   exit(f[k]);
end;
procedure combinesets(a,b:longint);
begin
 s[f[a]]:=(s[a]+1) mod 2;
 f[f[a]]:=b;
end;
procedure work;
var
 i,sa,sb:longint;
begin
 for i:=m downto 1 do
  begin
   sa:=findsets(a[i]); sb:=findsets(b[i]);
    if sa=sb then
     begin
      if s[a[i]]=s[b[i]] then
       begin
        writeln(c[i]);
         exit;
       end;
     end
     else combinesets(a[i],b[i]);
  end;
   writeln(0);
end;
procedure qsort(l,r:longint);
var
 i,j,x,y:longint;
begin
 i:=l; j:=r; x:=c[(l+r) div 2];
repeat
 while c[i]<x do inc(i);
 while c[j]>x do dec(j);
 if not (i>j) then
begin
y:=a[i]; a[i]:=a[j]; a[j]:=y;
y:=b[i]; b[i]:=b[j]; b[j]:=y;
y:=c[i]; c[i]:=c[j]; c[j]:=y;
inc(i); dec(j);
end;
until i>j;
if j>l then qsort(l,j);
if i<r then qsort(i,r);
end;
procedure makesets;
var
i:longint;
begin
for i:=1 to n do f[i]:=i;
end;
procedure reads;
var
i:longint;
begin
readln(n,m);
makesets;
for i:=1 to m do readln(a[i],b[i],c[i]);
end;
begin
//assign(input,'prison.in');
//reset(input);
//assign(output,'prison.out');
//rewrite(output);
reads;
qsort(1,m);
work;
//close(input);
//close(output);
end.
/**************************************************************
	Problem: 2298
	User: admin
	Language: Pascal
	Result: Wrong Answer
****************************************************************/