#include<stdio.h>
#include<stdlib.h>

int n,m;

struct nod{ unsigned short val;
            short dist;
           struct nod* urm;
           }*d[50001],*u[50001],*pc;
struct ant{ int val; struct ant* anter;}*ult;


int viz[50001],nc,dis[50001];


int main(void)
{
    
    freopen("dijkstra.in","r",stdin);
    freopen("dijkstra.out","w",stdout);
    scanf("%d %d",&n,&m);
    
    int i,len=sizeof(struct nod*);
for(i=1; i<=50000; i++)d[i]=u[i]=malloc(len);    
    
    
for(i=1; i<=m; i++)
{ int x,y,z; scanf("%d %d %d",&x,&y,&z);
  pc=malloc(len);
  if(viz[x]==0){pc->val=y; pc->urm=NULL; pc->dist=z; 
                d[x]->urm=pc; u[x]=pc; viz[x]=1;}
  else{ pc->val=y; pc->urm=NULL; pc->dist=z;
        u[x]->urm=pc; u[x]=pc;}
} 
printf("%d",u[4]->val);    
    
return 0;
}