#include<stdio.h>
#include<string.h>
#include<algorithm>
#define MAXD 410
#define MAXM 160010
#define INF 0x3f3f3f3f
int N, M, g[MAXD][MAXD], first[MAXD], e, next[MAXM], v[MAXM], flow[MAXM];
int S, T, q[MAXD], d[MAXD], work[MAXD], diss[MAXD], dist[MAXD], pre[MAXD];
void init()
{int i, x, y, z;memset(g, 0x3f, sizeof(g));for(i = 0; i < M; i ++){scanf("%d%d%d", &x, &y, &z);g[x][y] = g[y][x] = z;    }
}
void dij(int S, int T, int *dis)
{int i, j, k, min;memset(dis, 0x3f, sizeof(diss[0]) * (N + 1));memset(d, 0, sizeof(d[0]) * (N + 1));dis[S] = 0;for(;;){min = INF;for(i = 1; i <= N; i ++) if(!d[i] && dis[i] < min) min = dis[k = i];if(min == INF) break;d[k] = 1;for(i = 1; i <= N; i ++) dis[i] = std::min(dis[i], dis[k] + g[k][i]);}
}
int bfs()
{int i, j, rear = 0;memset(d, -1, sizeof(d[0]) * (N + 1));d[S] = 0, q[rear ++] = S;for(i = 0; i < rear; i ++)for(j = first[q[i]]; j != -1; j = next[j])if(flow[j] && d[v[j]] == -1){d[v[j]] = d[q[i]] + 1, q[rear ++] = v[j];if(v[j] == T) return 1;    }return 0;
}
int dfs(int cur, int a)
{if(cur == T) return a;for(int &i = work[cur]; i != -1; i = next[i])if(flow[i] && d[v[i]] == d[cur] + 1)if(int t = dfs(v[i], std::min(a, flow[i]))){flow[i] -= t, flow[i ^ 1] += t;return t;    }    return 0;
}
int dinic()
{int ans = 0, t;while(bfs()){memcpy(work, first, sizeof(first[0]) * (N + 1));while(t = dfs(S, INF))ans += t;}return ans;
}
void add(int x, int y, int z)
{v[e] = y, flow[e] = z;next[e] = first[x], first[x] = e ++;
}
void print()
{int i, cur = 1;for(;;){if(cur == T){printf("%d\n", cur);return ;    }printf("%d ", cur);for(i = first[cur]; i != -1; i = next[i])if((i & 1) == 0 && flow[i] == 0){flow[i] = 1, cur = v[i];break;    }}
}
void solve()
{int i, j;dij(1, N, diss), dij(N, 1, dist);if(diss[N] == INF){printf("No solution\n");return ;    }memset(first, -1, sizeof(first[0]) * (N + 1)), e = 0;for(i = 1; i <= N; i ++)for(j = 1; j <= N; j ++)if(i != j && diss[i] + g[i][j] + dist[j] == diss[N])add(i, j, 1), add(j, i, 0);S = 0, T = N;add(S, 1, 2), add(1, S, 0);if(dinic() != 2)printf("No solution\n");elseprint(), print();
}
int main()
{while(scanf("%d%d", &N, &M) == 2){init();solve();    }return 0;
}