#include<bits/stdc++.h>using namespace std;const int MAX = 100+10;vector<pair<int, int> > edges[MAX];int d[MAX];int main(){ int n, m; while (~scanf("%d %d", &n, &m)) { for (int i = 1; i <= n; i++) { edges[i].clear(); d[i] = 1e9; } for (int i = 0; i < m; i++) { int u, v, w; scanf("%d %d %d", &u, &v, &w); edges[u].push_back(make_pair(v, w)); edges[v].push_back(make_pair(u, w)); } int s = 1, t = n; priority_queue<pair<int, int> >q; d[s] = 0; q.push(make_pair(-d[s], s)); while (!q.empty()) { int u = q.top().second; q.pop(); for (int i = 0; i < edges[u].size(); i++) { int v = edges[u][i].first; if (d[v] > d[u] + edges[u][i].second) { d[v] = d[u] + edges[u][i].second; q.push(make_pair(-d[v], v)); } } } if (d[t] == 1e9) printf("-1/n"); else printf("%d/n", d[t]); }}
