#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>

using namespace std;
const int MAXN=101 ;
int N,M ;
double map[MAXN][MAXN] ;
double Max(double x,double y)
{
   return x>y ? x: y ;
}
double Mul(double x,double y)
{
    return x*y ;
}
void Floyd()
{
    int i,j,k ;
    for(k=1 ;k<=N ;k++)
      for(i=1 ;i<=N ;i++)
        for(j=1;j<=N ;j++)
        {
            if(map[i][k]!=0 && map[k][j]!=0)
              map[i][j]=Max(map[i][j],Mul(map[i][k],map[k][j])) ;
        }
}
int main()
{
  //  freopen("in.txt","r",stdin) ;
   int i ;
   while(cin>>N && N)
   {
       cin>>M ;
       memset(map,0.0,sizeof(map)) ;
       for(i=0 ;i<M ;i++)
       {
           int u,v ;
           double w ;
           cin>>u>>v>>w ;
           map[u][v]=w*0.01 ;
           map[v][u]=w*0.01 ;
       }
       Floyd() ;
     printf("%.6lf ", map[1][N]*100) ;
     cout<<"percent"<<endl ;
   }
    return 0;
}