1 #include<cstdio>
 2 #include<iostream>
 3
 4 using namespace std;
 5
 6 int g[105][105],dis[105][105],path[105][105];
 7 //path[i][j]表示i到j的最短路径中j的前一个点
 8 //dis[i][j]表示i到j最短的那条路径
 9 int n,m,ans[105],mi,cnt;
10
11 inline void chushihua() {
12     for(int i = 1;i <= n; i++)
13         for(int j = 1;j <= n; j++)
14             dis[i][j] = g[i][j] = 0x3f3f,path[i][j] = i;
15 }
16
17 inline void _read() {
18     int u,v,w;
19     for(int i = 1;i <= m; i++) {
20         scanf("%d%d%d",&u,&v,&w);
21         dis[u][v] = dis[v][u] = g[u][v] = g[v][u] = min(w,dis[u][v]);
22     }
23 }
24
25 inline void Floyd() {
26     mi = 0x3f3f;
27     for(int k = 1;k <= n; k++){
28         for(int i = 1;i < k; i++)
29             for(int j = 1;j < i; j++) {
30                 if(dis[i][j] + g[i][k] + g[k][j] < mi) {
31                     mi = dis[i][j] + g[i][k] + g[k][j];
32                     int tmp = j;
33                     cnt = 0;
34                     while(tmp != i) {
35                         ans[cnt++] = tmp;
36                         tmp = path[i][tmp];
37                     }
38                     ans[cnt++] = i;
39                     ans[cnt++] = k;
40                 }
41             }
42     for(int i = 1;i <= n; i++)
43         for(int j = 1;j <= n; j++) {
44             if(dis[i][k] + dis[k][j] < dis[i][j]) {
45                 dis[i][j] = dis[i][k] + dis[k][j];
46                 path[i][j] = path[k][j];
47             }
48         }
49     }
50 }
51
52 inline void _print() {
53     if(mi == 0x3f3f)
54         printf("No solution.");
55     else {
56         for(int i = 1;i < cnt; i++)
57             printf("%d ",ans[i]);
58         printf("%d",ans[0]);
59     }
60
61 }
62
63 int main()//简洁易懂的主函数
64 {
65     scanf("%d%d",&n,&m);
66     chushihua();
67     _read();
68     Floyd();
69     _print();
70     return 0;
71 }