#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

#define REP(i,n) for(int i=0;i<(int)n;++i)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)
#define ALL(c) (c).begin(), (c).end()

typedef int Weight;
const int INF = 1e9;
struct Edge {
    int src, dst;
    Weight weight;
    Edge(int src, int dst, Weight weight) :
        src(src), dst(dst), weight(weight) { }
};

bool operator < (const Edge &e, const Edge &f) {
  return e.weight != f.weight ? e.weight > f.weight : // !!INVERSE!!
    e.src != f.src ? e.src < f.src : e.dst < f.dst;
}
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

void shortestPath(const Graph &g, int s,
                  vector<Weight> &dist, vector<int> &prev) {
    int n = g.size();
    dist.assign(n, INF); dist[s] = 0;
    prev.assign(n, -1);
    priority_queue<Edge> Q; // "e < f" <=> "e.weight > f.weight"
    for (Q.push(Edge(-2, s, 0)); !Q.empty(); ) {
        Edge e = Q.top(); Q.pop();
        if (prev[e.dst] != -1) continue;
        prev[e.dst] = e.src;
        FOR(f,g[e.dst]) {
            if (dist[f->dst] > e.weight+f->weight) {
                dist[f->dst] = e.weight+f->weight;
                Q.push(Edge(f->src, f->dst, e.weight+f->weight));
            }
        }
    }
}

vector<int> buildPath(const vector<int> &prev, int t) {
    vector<int> path;
    for (int u = t; u >= 0; u = prev[u])
        path.push_back(u);
    reverse(path.begin(), path.end());
    return path;
}

int main()
{
    int n, m;
    char ch;

    while (cin >> n, n) {
        Graph g(n);
        vector<Weight> d;
        vector<int> prev, path;
        cin >> m;

        for (int i = 0; i < m; i++) {
            int u, v, w;

            cin >> u >> ch >> v >> ch >> w;
            w = w / 100 - 1;
            g[u].push_back(Edge(u, v, w));
            g[v].push_back(Edge(v, u, w));
        }
        shortestPath(g, 0, d, prev);
        path = buildPath(prev, n - 1);

        cout << d[n - 1] + path.size() + 2 << endl;
    }

    return 0;
}