#include <cstdio>
#include <iostream>
#include <fstream>
#include <cmath>
#include <algorithm>
#include <ctime>
#include <cctype>
#include <cstdlib>
#include <cassert>
#include <functional>
#include <iomanip>
#include <string>
#include <cstring>
#include <map>
#include <set>
#include <vector>
#include <queue>

using namespace std;

int s, f;

vector <pair <int, int> > g[3000];

queue < pair<int, int> > bfs;
const int INF = 1000000000;

int used[3000];

int am[5000];
int bm[5000];
int rm[5000];

string d[3000];

int ans = 1e9;

string sum(const string &a1, const string &b1)
{
   string a = a1;
    string b = b1;

    //длинное сложение
    //cerr << a << endl << b << endl;

    for(int i = 0; i < 2100; i++)
    {
        am[i] = 0;
        bm[i] = 0;
        rm[i] = 0;
    }

    int u1 = 1;
    int u2 = 1;

    if(a.size() > b.size())
    {
        int r = a.size() - b.size();

        u2 += r;
    }

    if(a.size() < b.size())
    {
        int r = b.size() - a.size();

        u1 += r;
    }

    //cerr << u1 << " " << u2 << endl;

    for(int i = u1; i < u1 + a.size(); i++)
        am[i] = a[i - u1] - '0';

    for(int i = u2; i < u2 + b.size(); i++)
        bm[i] = b[i - u2] - '0';

    for(int i = 0; i < u2 + b.size(); i++)
        rm[i] = am[i] + bm[i];

    for(int i = u2 + b.size(); i > 0; i--)
    {
        if(rm[i] >= 10)
        {
            rm[i] -= 10;
            rm[i - 1]++;
        }
    }

    string answer = "";

    int flag = 0;

    for(int i = 0; i < u1 + a.size(); i++)
    {
        if(rm[i] != 0)
            flag = 1;

        if(flag == 1)
            answer.push_back( char( int(rm[i]) + int('0') ) );
    }

    //cerr << answer << endl;

    return answer;
}


string rec(int x)
{
    if(d[x] == "")
    {

        if(x == s)
        {
            return("1");
        }

        string  res = "00000000";

        for(int i = 0; i < g[x].size(); i++)
        {
            if(used[g[x][i].first] == used[x] - g[x][i].second)
            {
                //cerr << "(" << res << " "  << rec(g[x][i].first) << ")" << endl;
                res = sum(res, rec(g[x][i].first) );
            }
        }

        d[x] = res;
        return res;
    }
    else
        return(d[x]);
}
int main ()
{


    int n, m;

    cin >> n >> m;

    for(int i = 0; i < 2000; i++)
        used[i] = 1e8;

    for(int i = 0; i < m; i++)
    {
        int a, b, c;
        scanf("%d%d%d", &a, &b, &c);

        a--;
        b--;

        g[a].push_back(make_pair(b, c));
        g[b].push_back(make_pair(a, c));
    }

    cin >> s >> f;
    s--;
    f--;

    vector<int> dist (n, INF),  p (n);
    dist[s] = 0;
    vector<char> u (n);

    for (int i=0; i<n; ++i) {
        int v = -1;
        for (int j=0; j<n; ++j)
            if (!u[j] && (v == -1 || dist[j] < dist[v]))
                v = j;
        if (dist[v] == INF)
            break;
        u[v] = true;

        for (size_t j=0; j<g[v].size(); ++j) {
            int to = g[v][j].first,
                len = g[v][j].second;
            if (dist[v] + len < dist[to]) {
                dist[to] = dist[v] + len;
                p[to] = v;
            }
        }
    }

    for(int i = 0; i < n; i++)
        used[i] = dist[i];


    if(used[f] == INF)
    {
        cout << 0;
        return 0;
    }

    int flag = 0;
    //return 0;

    string answer = rec(f);

    for(int i = 0; i < answer.size(); i++)
    {
        if(flag == 0 && answer[i] != '0')
        {
            flag = 1;
        }

        if(flag == 1)
            cout << answer[i];
    }

    //cout << rec(f);

    return 0;
}