#include <stdio.h>

#include <algorithm>

#include<string.h>

#include<queue>

using namespace std;

#define met(a, b) memset(a, b, sizeof(a))

#define MOD 1000000007

#define N 2050

#define INF 0x3f3f3f3f

typedef long long LL;

int n, m, G[N][N], vis[N];

double dist[N];

double Dijkstra(int s)

{

    for(int i=; i<=n; i++)

        dist[i] = G[s][i];

    vis[s] = ;

    for(int i=; i<=n; i++)

    {

        double Min = -INF;

        int Index = -;

        for(int j=; j<=n; j++)

        {

            if( !vis[j] && Min < dist[j])

            {

                Min = dist[j];

                Index = j;

            }

        }

        if(Index == -)break;

        vis[Index] = ;

        for(int j=; j<=n; j++)

        {

            if( !vis[j] && dist[j] < dist[Index]*G[Index][j]/100.0)

            {

                dist[j] = dist[Index]*G[Index][j]/100.0;

            }

        }

    }

    return dist[n];

}

void Init()

{

    for(int i=; i<=n; i++)

    {

        for(int j=; j<=n; j++)

            G[i][j] = -INF;

        dist[i] = -INF;

        G[i][i] = vis[i] = ;

    }

}

int main()

{

    int a, b, c;

    while(scanf("%d", &n), n)

    {

        Init();

        scanf("%d", &m);

        for(int i=; i<=m; i++)

        {

            scanf("%d%d%d", &a, &b, &c);

            G[a][b] = G[b][a] = max(G[a][b], c);

        }

        double ans = Dijkstra();

        printf("%.6f percent\n", ans);

    }

    return ;

}