#include<cstdio> 
#include<iostream>
#include<vector>
#include<cstring>
#include<queue>
using namespace std;
const int INF=1000000000 +10;
const int N=10000;

int inq[N],cnt[N],dis[N],p[N],n;
struct node{
    int u,d;
    node(int u,int d):u(u),d(d){}
};

vector<node>edge[N];
bool bellman_ford(int s){
    queue<int>Q;
    memset(inq,0,sizeof(inq));
    memset(cnt,0,sizeof(cnt));
    for(int i=0;i<n;i++)dis[i]=INF;
    dis[s]=0;
    inq[s]=true;
    Q.push(s);
    while(!Q.empty()){
        int u=Q.front();Q.pop();
        inq[u]=false;
        for(int i=0;i<edge[u].size();i++){
            node y=edge[u][i];
            if(dis[u]<INF && dis[y.u]> dis[u]+y.d){
                dis[y.u]=dis[u]+y.d;
                p[y.u]=u;
                if(!inq[y.u]){
                    Q.push(y.u);inq[y.u]=true;
                    if(++cnt[y.u]>n)return false;
                }
            }
        }
    }
}
int main(){
    int a,b,d,m;
    while(scanf("%d%d",&n,&m)==2 &&n){
        for(int i=0;i<n;i++)edge[i].clear();
        while(m--){
            scanf("%d%d%d",&a,&b,&d);
            edge[a].push_back(node(b,d));
            edge[b].push_back(node(a,d));
        }
        if(bellman_ford(0)) {
            for(int i=0;i<n;i++)cout<<i<<" "<<dis[i]<<endl;
        }
        else cout<<"false"<<endl;
    }
}