#include<stdio.h>  
#include<string.h>  
#include<algorithm>  
using namespace std;
int sum[3005], fa[3005];
int find(int x) {  //查找，压缩路径 
    if (fa[x] == -1)
        return x;
    return fa[x] = find(fa[x]);
}

int main() {
    int n, m, i, x, y, z, cnt, t1, t2;
    while (~scanf("%d%d", &n, &m)) {
        cnt = n - 1;
        memset(fa, -1, sizeof(fa));
        memset(sum, 0, sizeof(sum));
        for (i = 1; i <= m; i++)
        {
            scanf("%d%d%d", &x, &y, &z);
            if (x == y)
                continue;
            sum[x] += z;
            sum[y] += z;
            x = find(x);
            y = find(y);
            if (x != y)
            {
                fa[x] = y;
                cnt--;  //统计还剩多少点未连通 
            }
        }
        if (cnt == 0) {  //图连通 
            int minn = 0x3ffffff;
            for (int i = 1; i <= n; i++) {
                if (sum[i] < minn) {
                    minn = sum[i];
                }
            }
            printf("%d\n", minn);
        }
        else
            printf("0\n");
    }
    return 0;
}