import java.util.*;
public class bellmanFord{
    static class Edge{
        int src, dest, weigh;
        Edge(int s, int d, int w){
            src = s;
            dest = d;
            weigh = w;
        }
    }
    static void printPath(int vertex, int[] parent){
        if(vertex==-1) return;
        printPath(parent[vertex], parent);
        System.out.print(vertex+" ");

    }
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter no. of vertices and edges: ");
        int n = sc.nextInt();
        int e = sc.nextInt();
        int[] parent = new int[n];
        Edge[] edges = new Edge[e];
        int[] dist = new int[n];

        System.out.print("Enter the edges(src dest weight): ");
        for(int i=0;i<e;i++){
            int s = sc.nextInt();
            int d = sc.nextInt();
            int w = sc.nextInt();
            edges[i] = new Edge(s,d,w);
            
        }

        System.out.println("\nEnter source vertex: ");
        int s = sc.nextInt();

        for(int i=0;i<n;i++){
            dist[i] = 999;
            parent[i] = -1;
        }
        dist[s] = 0;

        for(int i=1;i<=n-1;i++){
            for(int j=0;j<e;j++){
                int sr = edges[j].src;
                int d = edges[j].dest;
                int w = edges[j].weigh;
                if(dist[sr]!=999 && dist[sr] + w < dist[d]){
                    dist[d] = dist[sr]+w;
                    parent[d] = sr;
                }


            }
        }
        boolean negcycle = false;

        for(int j=0;j<e;j++){
                int sr = edges[j].src;
                int d = edges[j].dest;
                int w = edges[j].weigh;
                if(dist[sr]!=999 && dist[sr] + w < dist[d]){
                    dist[d] = dist[sr]+w;
                    negcycle = true;
                    break;
                    
                }
        }
        if(negcycle){
            System.out.println("\nNegative cycle exists.");

        }else{
            System.out.println("\nShortest paths from source vertex " + s + ":\n");
            for(int i=0;i<n;i++){
                System.out.println("vertex: "+i);
                System.out.println("Cost: "+ dist[i]);
                System.out.println("Path: ");
                printPath(i, parent);
                System.out.println();
            }
        }
        sc.close();
    }
}