#include<bits/stdc++.h>
#define ull unsigned long long
#define ui unsigned int
#define ld long double
#define ll long long
#define lll __int128
#define fi first
#define se second
#define e emplace
#define eb emplace_back
#define db double
#define ef emplace_front
#define pii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define vp vector<pii>
#define mp make_pair
//#define LOCALJUDGE
//#define int ll
bool ST;
static const ll MOD=998244353,Phi=998244352,inv2=499122177,Root=3,iRoot=332748118;
static const ll inf=1073741823,INF=4557430888798830399;
static const double eps=1e-8,pi=3.1415926535;
char in[1<<20],*p1=in,*p2=in;
using namespace std;
// #define getchar() (p1==p2&&(p2=(p1=in)+fread(in,1,1<<20,stdin),p1==p2)?EOF:*p1++)
struct tup{int x,y,z;tup(int X=0,int Y=0,int Z=0){x=X,y=Y,z=Z;}};
namespace FastIO
{
template<typename T> inline void write(T x,char ch=' ')
{
if(is_same<char,T>::value)putchar(x);
else
{
if(x<0)x=-x,putchar('-');
static char st[50];int top=0;
do{st[top++]=x%10+'0',x/=10;}while(x);
while(top)putchar(st[--top]);
}
ch!='~'?putchar(ch):0;
}
inline void write(const char*x,char ch=' ')
{
for(int i=0;x[i]!='\0';++i)putchar(x[i]);
ch!='~'?putchar(ch):0;
}
inline void read(char&s){do s=getchar();while(s=='\n'||s==' ');}
inline void read(char s[])
{
int len=0;char st;
do st=getchar();while(st=='\n'||st==' ');
s[++len]=st,st=getchar();
while(st!='\n'&&st!=' ')s[++len]=st,st=getchar();
s[++len]='\0';
}
template<typename T> inline void read(T &s)
{
s=0;char ch=getchar();
while((ch>'9'||ch<'0')&&ch!='-')ch=getchar();
bool tf=(ch=='-')&&(ch=getchar());
while((ch>='0')&&(ch<='9'))s=(s<<1)+(s<<3)+ch-'0',ch=getchar();
s=(tf?-s:s);
}
template<typename T1,typename T2> inline void read(pair<T1,T2> &s){read(s.fi),read(s.se);}
template<typename T,typename...Args> inline void write(T x,Args...args){write(x,'~'),write(args...);}
template<typename T,typename...Args> inline void read(T&x,Args&...args){read(x),read(args...);}
}
using namespace FastIO;
namespace MTool
{
inline int Cadd(int a,int b){return (ll)a+b>=MOD?(ll)a+b-MOD:a+b;}
inline int Cdel(int a,int b){return a-b<0?a-b+MOD:a-b;}
inline int Cmul(int a,int b){return 1ll*a*b%MOD;}
inline int sqr(int a){return 1ll*a*a%MOD;}
inline void Madd(int&a,int b){a=((ll)a+b>=MOD?(ll)a+b-MOD:a+b);}
inline void Mdel(int&a,int b){a=(a-b<0?a-b+MOD:a-b);}
inline void Mmul(int&a,int b){a=1ll*a*b%MOD;}
template<typename T> inline bool Mmax(T&a,T b){return a<b?a=b,1:0;}
template<typename T> inline bool Mmin(T&a,T b){return a>b?a=b,1:0;}
template<typename...Args> inline void Madd(int&a,int b,Args...args){Madd(a,b),Madd(a,args...);}
template<typename...Args> inline void Mmul(int&a,int b,Args...args){Mmul(a,b),Mmul(a,args...);}
template<typename...Args> inline void Mdel(int&a,int b,Args...args){Mdel(a,b),Mdel(a,args...);}
template<typename...Args> inline int Cadd(int a,int b,Args...args){return Cadd(Cadd(a,b),args...);}
template<typename...Args> inline int Cmul(int a,int b,Args...args){return Cmul(Cmul(a,b),args...);}
template<typename...Args> inline int Cdel(int a,int b,Args...args){return Cdel(Cdel(a,b),args...);}
template<typename...Args,typename T> inline bool Mmax(T&a,T b,Args...args){return Mmax(a,b)|Mmax(a,args...);}
template<typename...Args,typename T> inline bool Mmin(T&a,T b,Args...args){return Mmin(a,b)|Mmin(a,args...);}
inline int power(int x,int y){int s=1;for(;y;y>>=1,Mmul(x,x))if(y&1)Mmul(s,x);return s;}
}
using namespace MTool;
namespace WrongAnswer_90
{
int n,m,ans,fa[200010];
tup b[500010];
int find(int x){return x==fa[x]?x:fa[x]=find(fa[x]);}
inline bool cmp(tup x,tup y){return x.z<y.z;}
inline void mian()
{
read(n,m);
for(int i=1;i<=n;++i)fa[i]=i;
for(int i=1;i<=m;++i)read(b[i].x,b[i].y,b[i].z);
sort(b+1,b+1+m,cmp);
for(int i=1;i<=m;++i)
{
int x=find(b[i].x),y=find(b[i].y);
if(x==y)continue;
ans+=z,fa[x]=y;
}
write(ans);
}
}
bool ED;
signed main()
{
#ifdef LOCALJUDGE
freopen("ex_mod5.in","r",stdin);
freopen("1.out","w",stdout);
#endif
double st=clock();
WrongAnswer_90::mian();
double ed=clock();
#ifndef LOCALJUDGE
cerr<<endl;
#endif
cerr<<"Time: "<<ed-st<<" ms\n";
#ifdef LOCALJUDGE
cerr<<" ";
#endif
cerr<<"Memory: "<<abs(&ST-&ED)/1024.0/1024.0<<" MB\n";
return 0;
}