#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <string>
#include <queue>
#include <stack>
#include <map>
#include <utility>

using namespace std;
typedef long long LL;
typedef pair<LL, LL> PLL;
const LL INF=4e18;

const int MAXM=1e5+10;
struct GX {
    LL u,v,w;
} a[MAXM];

bool mycmp(const GX &x, const GX &y) {
    if (x.u!=y.u) {
        return x.u<y.u;
    } else if (x.v!=y.v) {
        return x.v<y.v;
    } else {
        return x.w<y.w;
    }
}

//并查集
const int MAXN=3e3+10;
LL sum[MAXN];
LL fa[MAXN];//父亲
LL sa[MAXN];//集合内数据个数
void init(LL n) {
    for (LL i=0; i<=n; i++) {
        fa[i]=i;
        sa[i]=0;
    }
}

//找x父亲
LL find(LL x) {
    if (fa[x]!=x) {
        fa[x]=find(fa[x]);
    }
    return fa[x];
}

//合并x,y
bool join(LL x, LL y) {
    x=find(x);
    y=find(y);
    if (x==y) {
        return false;
    }
    if (sa[x]<sa[y]) {
        swap(x, y);
    }
    fa[x]=y;
    sa[y]+=sa[x];
    return true;
}

int main() {
#if 1
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
#endif
    //freopen("r","00.in", stdin);
    //freopen("w","00.out", stdout);
    LL n,m;
    LL cnt;
    while (cin>>n>>m) {
        //初始化
        init(n);
        cnt=0;
        memset(sum, 0, sizeof(sum));

        for (LL i=1; i<=m; i++) {
            LL u,v,w;
            cin>>u>>v>>w;

            if (u==v) {
                continue;
            }
            sum[u]+=w;
            sum[v]+=w;
            if (join(u, v)) {
                cnt++;
            }
            //cin>>a[i].u>>a[i].v>>a[i].w;
        }

        if (cnt==n-1) {
            sort(sum+1, sum+n+1);
            cout<<sum[1]<<"\n";
        } else {
            cout<<"0\n";
        }
    }
    return 0;
}