#include <iostream>
#include <vector>
#include <stdio.h>
#include <string.h>

using namespace std;

int n, m, u, v, p, ans, matrix[2020][2020], matrixB[2020][2020], vis[2020];

int dfs1(int x) {
    ans++;
    vis[x] = 1;
    for(int i = 1; i <= n; i++) {
        if(vis[i] == 0&& matrix[x][i] == 1) dfs1(i);
    }
}

int dfs2(int x) {
    ans++;
    vis[x] = 1;
    for(int i = 1; i <= n; i++) {
        if(vis[i] == 0&& matrixB[x][i] == 1) dfs2(i);
    }
}

int main(void) {
    while(cin >> n >> m && !(n == 0 && m == 0)) {
        memset(matrix, 0, sizeof(matrix)); memset(matrixB, 0, sizeof(matrixB));
        for(int i = 0; i < m; i++) {
            scanf("%d%d%d", &u, &v, &p);
            if(p == 1) {
                matrix[u][v] = 1;
                matrixB[v][u] = 1;
            } else {
                matrix[u][v] = 1;
                matrix[v][u] = 1;
                matrixB[u][v] = 1;
                matrixB[v][u] = 1;
            }
        }
        memset(vis, 0, sizeof(vis));
        ans = 0;
        dfs1(1);
        if(ans != n) {
            printf("0\n");
        } else {
            memset(vis, 0, sizeof(vis));
            ans = 0; dfs2(1);
            if(ans != n) {
                printf("0\n");
            } else {
                printf("1\n");
            }
        }
    }
    return 0;
}